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 Deep Learning


VideoBERT: A Joint Model for Video and Language Representation Learning

arXiv.org Artificial Intelligence

Self-supervised learning has become increasingly important Deep learning can benefit a lot from labeled data [23], to leverage the abundance of unlabeled data available but this is hard to acquire at scale. Consequently there has on platforms like YouTube. Whereas most existing been a lot of recent interest in "self supervised learning", approaches learn low-level representations, we propose a where we train a model on various "proxy tasks", which joint visual-linguistic model to learn high-level features we hope will result in the discovery of features or representations without any explicit supervision. In particular, inspired that can be used in downstream tasks (see e.g., by its recent success in language modeling, we build upon [22]). A wide variety of such proxy tasks have been proposed the BERT model to learn bidirectional joint distributions in the image and video domains. However, most of over sequences of visual and linguistic tokens, derived from these methods focus on low level features (e.g., textures) vector quantization of video data and off-the-shelf speech and short temporal scales (e.g., motion patterns that last a recognition outputs, respectively. We use this model in a second or less). We are interested in discovering high-level number of tasks, including action classification and video semantic features which correspond to actions and events captioning. We show that it can be applied directly to openvocabulary that unfold over longer time scales (e.g.


Bringing AI to the Edge

#artificialintelligence

In a little over a decade since researchers uncovered novel techniques to improve its efficiency and effectiveness, deep learning has become a practical technology that now underpins a number of applications that need artificial intelligence (AI). Many of these applications are hosted in the cloud on powerful servers, as tasks sometimes involve the processing of data-rich sources such as images, videos, and audio. Those servers often call on the additional performance of acceleration hardware, which range from graphics processing units to custom devices. These become particularly important for the numerically-intensive process, during which a neural network is trained on new data. Typically, the inferencing process, which uses a trained network to assess new data, is far less compute-intensive than training.


How Can We Be So Dense? The Benefits of Using Highly Sparse Representations

arXiv.org Machine Learning

Most artificial networks today rely on dense representations, whereas biological networks rely on sparse representations. In this paper we show how sparse representations can be more robust to noise and interference, as long as the underlying dimensionality is sufficiently high. A key intuition that we develop is that the ratio of the operable volume around a sparse vector divided by the volume of the representational space decreases exponentially with dimensionality. We then analyze computationally efficient sparse networks containing both sparse weights and activations. Simulations on MNIST and the Google Speech Command Dataset show that such networks demonstrate significantly improved robustness and stability compared to dense networks, while maintaining competitive accuracy. We discuss the potential benefits of sparsity on accuracy, noise robustness, hyperparameter tuning, learning speed, computational efficiency, and power requirements.


A Strong Baseline for Domain Adaptation and Generalization in Medical Imaging

arXiv.org Artificial Intelligence

This work provides a strong baseline for the problem of multi-source multi-target domain adaptation and generalization in medical imaging. Using a diverse collection of ten chest X-ray datasets, we empirically demonstrate the benefits of training medical imaging deep learning models on varied patient populations for generalization to out-of-sample domains.


Lautum Regularization for Semi-supervised Transfer Learning

arXiv.org Machine Learning

Transfer learning is a very important tool in deep learning as it allows propagating information from one "source dataset" to another "target dataset", especially in the case of a small number of training examples in the latter. Yet, discrepancies between the underlying distributions of the source and target data are commonplace and are known to have a substantial impact on algorithm performance. In this work we suggest a novel information theoretic approach for the analysis of the performance of deep neural networks in the context of transfer learning. We focus on the task of semi-supervised transfer learning, in which unlabeled samples from the target dataset are available during the network training on the source dataset. Our theory suggests that one may improve the transferability of a deep neural network by imposing a Lautum information based regularization that relates the network weights to the target data. We demonstrate in various transfer learning experiments the effectiveness of the proposed approach.


Are Learned Molecular Representations Ready For Prime Time?

arXiv.org Machine Learning

Advancements in neural machinery have led to a wide range of algorithmic solutions for molecular property prediction. Two classes of models in particular have yielded promising results: neural networks applied to computed molecular fingerprints or expert-crafted descriptors, and graph convolutional neural networks that construct a learned molecular representation by operating on the graph structure of the molecule. However, recent literature has yet to clearly determine which of these two methods is superior when generalizing to new chemical space. Furthermore, prior research has rarely examined these new models in industry research settings in comparison to existing employed models. In this paper, we benchmark models extensively on 19 public and 15 proprietary industrial datasets spanning a wide variety of chemical endpoints. In addition, we introduce a graph convolutional model that consistently outperforms models using fixed molecular descriptors as well as previous graph neural architectures on both public and proprietary datasets. Our empirical findings indicate that while approaches based on these representations have yet to reach the level of experimental reproducibility, our proposed model nevertheless offers significant improvements over models currently used in industrial workflows.


Interplay Between Optimization and Generalization of Stochastic Gradient Descent with Covariance Noise

arXiv.org Machine Learning

The choice of batch-size in a stochastic optimization algorithm plays a substantial role for both optimization and generalization. Increasing the batch-size used typically improves optimization but degrades generalization. To address the problem of improving generalization while maintaining optimal convergence in large-batch training, we propose to add covariance noise to the gradients. We demonstrate that the optimization performance of our method is more accurately captured by the structure of the noise covariance matrix rather than by the variance of gradients. Moreover, over the convex-quadratic, we prove in theory that it can be characterized by the Frobenius norm of the noise matrix. Our empirical studies with standard deep learning model-architectures and datasets shows that our method not only improves generalization performance in large-batch training, but furthermore, does so in a way where the optimization performance remains desirable and the training duration is not elongated.


Measuring Calibration in Deep Learning

arXiv.org Machine Learning

The reliability of a machine learning model's confidence in its predictions is critical for highrisk applications. Calibration-the idea that a model's predicted probabilities of outcomes reflect true probabilities of those outcomes-formalizes this notion. While analyzing the calibration of deep neural networks, we've identified core problems with the way calibration is currently measured. We design the Thresholded Adaptive Calibration Error (TACE) metric to resolve these pathologies and show that it outperforms other metrics, especially in settings where predictions beyond the maximum prediction that is chosen as the output class matter. There are many cases where what a practitioner cares about is the calibration of a specific prediction, and so we introduce a dynamic programming based Prediction Specific Calibration Error (PSCE) that smoothly considers the calibration of nearby predictions to give an estimate of the calibration error of a specific prediction.


Peak Alignment of GC-MS Data with Deep Learning

arXiv.org Machine Learning

GC-MS is regarded as a gold standard in analysis of chemical composition in samples. However, due to the complexity of the instrument, a substance's retention time (RT) may not stay fixed across multiple GC-MS chromatograms. To use GC-MS data for biomarker discovery requires alignment of identical analyte's RT from different samples. Current methods of alignment are all based on a set of formal, mathematical rules, consequently, they are unable to handle the complexity of GC-MS data from human breath. We present a solution to GC-MS alignment using deep learning neural networks, which are more adept at complex, fuzzy data sets. We tested our model on several GC-MS data sets of various complexities and show the model has very good true position rates (up to 99% for easy data sets and up to 92% for very complex data sets). We compared our model with the popular correlation optimized warping (COW) and show our model has much better overall performance. This method can easily be adapted to other similar data such as those from liquid chromatography.


The Verbal and Non Verbal Signals of Depression -- Combining Acoustics, Text and Visuals for Estimating Depression Level

arXiv.org Artificial Intelligence

Depression is a serious medical condition that is suffered by a large number of people around the world. It significantly affects the way one feels, causing a persistent lowering of mood. In this paper, we propose a novel attention-based deep neural network which facilitates the fusion of various modalities. We use this network to regress the depression level. Acoustic, text and visual modalities have been used to train our proposed network. Various experiments have been carried out on the benchmark dataset, namely, Distress Analysis Interview Corpus - a Wizard of Oz (DAIC-WOZ). From the results, we empirically justify that the fusion of all three modalities helps in giving the most accurate estimation of depression level. Our proposed approach outperforms the state-of-the-art by 7.17% on root mean squared error (RMSE) and 8.08% on mean absolute error (MAE).