Government
Data Scientist
Accenture Federal Services delivers a range of innovative, tech-enabled services for the U.S. Federal Government to address the complex, sensitive challenges of national security and intelligence missions. Refer a qualified candidate and earn up to $10K. Accenture Federal Services is seeking a CI Targeter, to explore new data sources, create effective queries, and combine information from disparate sources to produce written products and verbal briefings that help the client understand their operational landscape and mission environment. You will validate information and apply client tradecraft to help build assessments for both the warfighter and key policy makers. Accenture Federal Services is committed to providing veteran employment opportunities to our service men and women.
How do you define IoT and Industry 4.0? - ISA
Conferences, media, vendors, automation industry consultants, business consultants, and even politicians are discussing and making presentations about how the Internet of Things (IoT) and Industry 4.0 are creating a revolution in manufacturing. I am convinced we are at a juncture of major industrial automation changes driven by technology advancements. The digital revolution of business functions, including accounting, supply chain, human resources, procurement, customer services, business intelligence, and distribution management, has been refined over multiple generations. In contrast, the industrial and process automation industries have not transformed at the same rate. They must be digitized now for manufacturers to compete. At the end of this article I have the results of a small survey of readers that may be interesting.
Assessments of epistemic uncertainty using Gaussian stochastic weight averaging for fluid-flow regression
Morimoto, Masaki, Fukami, Kai, Maulik, Romit, Vinuesa, Ricardo, Fukagata, Koji
We use Gaussian stochastic weight averaging (SWAG) to assess the model-form uncertainty associated with neural-network-based function approximation relevant to fluid flows. SWAG approximates a posterior Gaussian distribution of each weight, given training data, and a constant learning rate. Having access to this distribution, it is able to create multiple models with various combinations of sampled weights, which can be used to obtain ensemble predictions. The average of such an ensemble can be regarded as the `mean estimation', whereas its standard deviation can be used to construct `confidence intervals', which enable us to perform uncertainty quantification (UQ) with regard to the training process of neural networks. We utilize representative neural-network-based function approximation tasks for the following cases: (i) a two-dimensional circular-cylinder wake; (ii) the DayMET dataset (maximum daily temperature in North America); (iii) a three-dimensional square-cylinder wake; and (iv) urban flow, to assess the generalizability of the present idea for a wide range of complex datasets. SWAG-based UQ can be applied regardless of the network architecture, and therefore, we demonstrate the applicability of the method for two types of neural networks: (i) global field reconstruction from sparse sensors by combining convolutional neural network (CNN) and multi-layer perceptron (MLP); and (ii) far-field state estimation from sectional data with two-dimensional CNN. We find that SWAG can obtain physically-interpretable confidence-interval estimates from the perspective of model-form uncertainty. This capability supports its use for a wide range of problems in science and engineering.
Work In Progress: Safety and Robustness Verification of Autoencoder-Based Regression Models using the NNV Tool
Pal, Neelanjana, Johnson, Taylor T
State-of-the-art and well-trained neural networks (NN) can easily be attacked by small perturbations in inputs, leading to significant aberrations in their outputs [14, 23, 33]. These input perturbations are not only limited to image-based networks but also apply to other input types as well, e.g., time-series data or input signals. Such lack of robustness poses serious risks to information integrity, privacy and security, and can be catastrophic in safety-critical applications [11, 29]. While verification of NNs with image inputs is a vastly growing research area; specifically, with recent ongoing works on safety and robustness checking of feedforward (FFNN), convolutional (CNN), and semantic segmentation networks (SSN); less has been done in the domain of autoencoder verification. Classification models using autoencoders work almost similar to usual classifiers, but there is a need for new research to develop verification techniques for regression models. The regression-based autoencoders regenerate the input in its output and thus can be checked using verification techniques whether the recreated output comes within a certain accepted range of the unperturbed input, in case there is a certain fault/attack on its input side. In a prior work, the authors of [36] introduced a novel framework for NN verification named Neural Network Verification (NNV) [38] tool, capable of evaluating the robustness of several DNN architectures, e.g., FFNN, CNN, SSN, etc. Later, a new set-based approach, Imagestar [34, 36] is also incorporated into this tool. In this work in progress work, we explore similar methods in the context of autoencoder verification via experimenting on a sampled dataset and checking if the output lies within a pre-determined safe threshold around the corresponding uninterrupted input values, given a specific type of fault in the input.
Permutationless Many-Jet Event Reconstruction with Symmetry Preserving Attention Networks
Fenton, Michael James, Shmakov, Alexander, Ho, Ta-Wei, Hsu, Shih-Chieh, Whiteson, Daniel, Baldi, Pierre
Top quarks, produced in large numbers at the Large Hadron Collider, have a complex detector signature and require special reconstruction techniques. The most common decay mode, the "all-jet" channel, results in a 6-jet final state which is particularly difficult to reconstruct in $pp$ collisions due to the large number of permutations possible. We present a novel approach to this class of problem, based on neural networks using a generalized attention mechanism, that we call Symmetry Preserving Attention Networks (SPA-Net). We train one such network to identify the decay products of each top quark unambiguously and without combinatorial explosion as an example of the power of this technique.This approach significantly outperforms existing state-of-the-art methods, correctly assigning all jets in $93.0%$ of $6$-jet, $87.8%$ of $7$-jet, and $82.6%$ of $\geq 8$-jet events respectively.
Distributionally Robust Deep Learning using Hardness Weighted Sampling
Fidon, Lucas, Aertsen, Michael, Deprest, Thomas, Emam, Doaa, Guffens, Frรฉdรฉric, Mufti, Nada, Van Elslander, Esther, Schwartz, Ernst, Ebner, Michael, Prayer, Daniela, Kasprian, Gregor, David, Anna L., Melbourne, Andrew, Ourselin, Sรฉbastien, Deprest, Jan, Langs, Georg, Vercauteren, Tom
Limiting failures of machine learning systems is of paramount importance for safety-critical applications. In order to improve the robustness of machine learning systems, Distributionally Robust Optimization (DRO) has been proposed as a generalization of Empirical Risk Minimization (ERM). However, its use in deep learning has been severely restricted due to the relative inefficiency of the optimizers available for DRO in comparison to the wide-spread variants of Stochastic Gradient Descent (SGD) optimizers for ERM. We propose SGD with hardness weighted sampling, a principled and efficient optimization method for DRO in machine learning that is particularly suited in the context of deep learning. Similar to a hard example mining strategy in practice, the proposed algorithm is straightforward to implement and computationally as efficient as SGD-based optimizers used for deep learning, requiring minimal overhead computation. In contrast to typical ad hoc hard mining approaches, we prove the convergence of our DRO algorithm for over-parameterized deep learning networks with ReLU activation and a finite number of layers and parameters. Our experiments on fetal brain 3D MRI segmentation and brain tumor segmentation in MRI demonstrate the feasibility and the usefulness of our approach. Using our hardness weighted sampling for training a state-of-the-art deep learning pipeline leads to improved robustness to anatomical variabilities in automatic fetal brain 3D MRI segmentation using deep learning and to improved robustness to the image protocol variations in brain tumor segmentation. Our code is available at https://github.com/LucasFidon/HardnessWeightedSampler.
GrabQC: Graph based Query Contextualization for automated ICD coding
Chelladurai, Jeshuren, Santhiappan, Sudarsun, Ravindran, Balaraman
Automated medical coding is a process of codifying clinical notes to appropriate diagnosis and procedure codes automatically from the standard taxonomies such as ICD (International Classification of Diseases) and CPT (Current Procedure Terminology). The manual coding process involves the identification of entities from the clinical notes followed by querying a commercial or non-commercial medical codes Information Retrieval (IR) system that follows the Centre for Medicare and Medicaid Services (CMS) guidelines. We propose to automate this manual process by automatically constructing a query for the IR system using the entities auto-extracted from the clinical notes. We propose \textbf{GrabQC}, a \textbf{Gra}ph \textbf{b}ased \textbf{Q}uery \textbf{C}ontextualization method that automatically extracts queries from the clinical text, contextualizes the queries using a Graph Neural Network (GNN) model and obtains the ICD Codes using an external IR system. We also propose a method for labelling the dataset for training the model. We perform experiments on two datasets of clinical text in three different setups to assert the effectiveness of our approach. The experimental results show that our proposed method is better than the compared baselines in all three settings.
Insurgency as Complex Network: Image Co-Appearance and Hierarchy in the PKK
Despite a growing recognition of the importance of insurgent group structure on conflict outcomes, there is very little empirical research thereon. Though this problem is rooted in the inaccessibility of data on militant group structure, insurgents frequently publish large volumes of image data on the internet. In this paper, I develop a new methodology that leverages this abundant but underutilized source of data by automating the creation of a social network graph based on co-appearance in photographs using deep learning. Using a trove of 19,115 obituary images published online by the PKK, a Kurdish militant group in Turkey, I demonstrate that an individual's centrality in the resulting co-appearance network is closely correlated with their rank in the insurgent group.
Adversarial Attacks on Monocular Pose Estimation
Chawla, Hemang, Varma, Arnav, Arani, Elahe, Zonooz, Bahram
Advances in deep learning have resulted in steady progress in computer vision with improved accuracy on tasks such as object detection and semantic segmentation. Nevertheless, deep neural networks are vulnerable to adversarial attacks, thus presenting a challenge in reliable deployment. Two of the prominent tasks in 3D scene-understanding for robotics and advanced drive assistance systems are monocular depth and pose estimation, often learned together in an unsupervised manner. While studies evaluating the impact of adversarial attacks on monocular depth estimation exist, a systematic demonstration and analysis of adversarial perturbations against pose estimation are lacking. We show how additive imperceptible perturbations can not only change predictions to increase the trajectory drift but also catastrophically alter its geometry. We also study the relation between adversarial perturbations targeting monocular depth and pose estimation networks, as well as the transferability of perturbations to other networks with different architectures and losses. Our experiments show how the generated perturbations lead to notable errors in relative rotation and translation predictions and elucidate vulnerabilities of the networks.
Leakage and the Reproducibility Crisis in ML-based Science
Kapoor, Sayash, Narayanan, Arvind
The use of machine learning (ML) methods for prediction and forecasting has become widespread across the quantitative sciences. However, there are many known methodological pitfalls, including data leakage, in ML-based science. In this paper, we systematically investigate reproducibility issues in ML-based science. We show that data leakage is indeed a widespread problem and has led to severe reproducibility failures. Specifically, through a survey of literature in research communities that adopted ML methods, we find 17 fields where errors have been found, collectively affecting 329 papers and in some cases leading to wildly overoptimistic conclusions. Based on our survey, we present a fine-grained taxonomy of 8 types of leakage that range from textbook errors to open research problems. We argue for fundamental methodological changes to ML-based science so that cases of leakage can be caught before publication. To that end, we propose model info sheets for reporting scientific claims based on ML models that would address all types of leakage identified in our survey. To investigate the impact of reproducibility errors and the efficacy of model info sheets, we undertake a reproducibility study in a field where complex ML models are believed to vastly outperform older statistical models such as Logistic Regression (LR): civil war prediction. We find that all papers claiming the superior performance of complex ML models compared to LR models fail to reproduce due to data leakage, and complex ML models don't perform substantively better than decades-old LR models. While none of these errors could have been caught by reading the papers, model info sheets would enable the detection of leakage in each case.