Deep Learning
A reality check for seemingly unstoppable progress in AI
The big picture: For the past 5 years, Elon Musk and others have warned of a future disaster resulting from unchecked superintelligent AI. But today, much of the field is caught in a rather more elementary tug-of-war over which avenue will imbue AI even with the capacity for basic understanding. Since the field took shape in the 1950s, artificial intelligence has advanced in fits and starts, with various tribes claiming the vanguard at different points. The current period began in the early 2010s, when a trio of researchers in Canada brought AI out of a decadeslong funk by reviving deep learning, aided by new and powerful hardware. Now, some of those same pioneers are warning against leaning too heavily on their contributions, and researchers with one foot in adjacent fields are sounding an increasingly insistent alarm about AI's trajectory.
r/MachineLearning - [D] Why is PyTorch as fast as (and sometimes faster than) TensorFlow?
Since both libraries use cuDNN under the hood, I would expect the individual operations to be similar in speed. However, TensorFlow (in graph mode) compiles a graph so when you run the actual train loop, you have no python overhead outside of the session.run In PyTorch, you are in Python a lot due to the dynamic graph, so I would expect that to add some overhead. Not to mention the fact that having a static graph means you can graph optimizations like node pruning and ordering operations. But in many benchmarks I see online, PyTorch has no problems keeping up with TensorFlow on GPUs.
O-MedAL: Online Active Deep Learning for Medical Image Analysis
Smailagic, Asim, Costa, Pedro, Gaudio, Alex, Khandelwal, Kartik, Mirshekari, Mostafa, Fagert, Jonathon, Walawalkar, Devesh, Xu, Susu, Galdran, Adrian, Zhang, Pei, Campilho, Aurรฉlio, Noh, Hae Young
Active Learning methods create an optimized and labeled training set from unlabeled data. We introduce a novel Online Active Deep Learning method for Medical Image Analysis. We extend our MedAL active learning framework to present new results in this paper. Experiments on three medical image datasets show that our novel online active learning model requires significantly less labelings, is more accurate, and is more robust to class imbalances than existing methods. Our method is also more accurate and computationally efficient than the baseline model. Compared to random sampling and uncertainty sampling, the method uses 275 and 200 (out of 768) fewer labeled examples, respectively. For Diabetic Retinopathy detection, our method attains a 5.88% accuracy improvement over the baseline model when 80% of the dataset is labeled, and the model reaches baseline accuracy when only 40% is labeled.
Is the Red Square Big? MALeViC: Modeling Adjectives Leveraging Visual Contexts
Pezzelle, Sandro, Fernรกndez, Raquel
This work aims at modeling how the meaning of gradable adjectives of size (`big', `small') can be learned from visually-grounded contexts. Inspired by cognitive and linguistic evidence showing that the use of these expressions relies on setting a threshold that is dependent on a specific context, we investigate the ability of multi-modal models in assessing whether an object is `big' or `small' in a given visual scene. In contrast with the standard computational approach that simplistically treats gradable adjectives as `fixed' attributes, we pose the problem as relational: to be successful, a model has to consider the full visual context. By means of four main tasks, we show that state-of-the-art models (but not a relatively strong baseline) can learn the function subtending the meaning of size adjectives, though their performance is found to decrease while moving from simple to more complex tasks. Crucially, models fail in developing abstract representations of gradable adjectives that can be used compositionally.
Nuclear Instance Segmentation using a Proposal-Free Spatially Aware Deep Learning Framework
Koohbanani, Navid Alemi, Jahanifar, Mostafa, Gooya, Ali, Rajpoot, Nasir
Nuclear segmentation in histology images is a challenging task due to significant variations in the shape and appearance of nuclei. One of the main hurdles in nuclear instance segmentation is overlapping nuclei where a smart algorithm is needed to separate each nucleus. In this paper, we introduce a proposal-free deep learning based framework to address these challenges. To this end, we propose a spatially-aware network (SpaNet) to capture spatial information in a multi-scale manner. A dual-head variation of the SpaNet is first utilized to predict the pixel-wise segmentation and centroid detection maps of nuclei. Based on these outputs, a single-head SpaNet predicts the positional information related to each nucleus instance. Spectral clustering method is applied on the output of the last SpaNet, which utilizes the nuclear mask and the Gaussian-like detection map for determining the connected components and associated cluster identifiers, respectively. The output of the clustering method is the final nuclear instance segmentation mask. We applied our method on a publicly available multi-organ data set and achieved state-of-the-art performance for nuclear segmentation.
Intelligent Active Queue Management Using Explicit Congestion Notification
Gomez, Cesar A., Wang, Xianbin, Shami, Abdallah
--As more end devices are getting connected, the Internet will become more congested. Various congestion control techniques have been developed either on transport or network layers. Active Queue Management (AQM) is a paradigm that aims to mitigate the congestion on the network layer through active buffer control to avoid overflow. However, finding the right parameters for an AQM scheme is challenging, due to the complexity and dynamics of the networks. On the other hand, the Explicit Congestion Notification (ECN) mechanism is a solution that makes visible incipient congestion on the network layer to the transport layer. In this work, we propose to exploit the ECN information to improve AQM algorithms by applying Machine Learning techniques. Our intelligent method uses an artificial neural network to predict congestion and an AQM parameter tuner based on reinforcement learning. The evaluation results show that our solution can enhance the performance of deployed AQM, using the existing TCP congestion control mechanisms. Thanks to the proliferation of smart devices and the paradigm of Internet of Things (IoT), the demand for connections to the Internet is dramatically growing.
Inception-inspired LSTM for Next-frame Video Prediction
Hosseini, Matin, Maida, Anthony S., Hosseini, Majid, Raju, Gottumukkala
The problem of video frame prediction has received much interest due to its relevance to many computer vision applications such as autonomous vehicles or robotics. Supervised methods for video frame prediction rely on labeled data, which may not always be available. In this paper, we provide a novel unsupervised deep-learning method called Inception-based LSTM for video frame prediction. The general idea of inception networks is to implement wider networks instead of deeper networks. This network design was shown to improve the performance of image classification. The proposed method is evaluated on both Inception-v1 and Inception-v2 structures. The proposed Inception LSTM methods are compared with convolutional LSTM when applied using PredNet predictive coding framework for both the KITTI and KTH data sets. We observed that the Inception based LSTM outperforms the convolutional LSTM. Also, Inception LSTM has better prediction performance compared to Inception v2 LSTM. However, Inception v2 LSTM has a lower computational cost compared to Inception LSTM.
Stock Price Forecasting and Hypothesis Testing Using Neural Networks
In this work we use Recurrent Neural Networks and Multilayer Perceptrons to predict NYSE, NASDAQ and AMEX stock prices from historical data. We experiment with different architectures and compare data normalization techniques. Then, we leverage those findings to question the efficient-market hypothesis through a formal statistical test.
Multiresolution Transformer Networks: Recurrence is Not Essential for Modeling Hierarchical Structure
Garg, Vikas K., Dhillon, Inderjit S., Yu, Hsiang-Fu
The architecture of Transformer is based entirely on self-attention, and has been shown to outperform models that employ recurrence on sequence transduction tasks such as machine translation. The superior performance of Transformer has been attributed to propagating signals over shorter distances, between positions in the input and the output, compared to the recurrent architectures. We establish connections between the dynamics in Transformer and recurrent networks to argue that several factors including gradient flow along an ensemble of multiple weakly dependent paths play a paramount role in the success of Transformer. We then leverage the dynamics to introduce {\em Multiresolution Transformer Networks} as the first architecture that exploits hierarchical structure in data via self-attention. Our models significantly outperform state-of-the-art recurrent and hierarchical recurrent models on two real-world datasets for query suggestion, namely, \aol and \amazon. In particular, on AOL data, our model registers at least 20\% improvement on each precision score, and over 25\% improvement on the BLEU score with respect to the best performing recurrent model. We thus provide strong evidence that recurrence is not essential for modeling hierarchical structure.