A Primer on Machine Learning
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Backpropagation and Deep Learning in the Brain
Backpropagation and Deep Learning in the Brain Simons Institute -- Computational Theories of the Brain 2018 Timothy Lillicrap DeepMind, UCL With: Sergey Bartunov, Adam Santoro, Jordan Guerguiev, Blake Richards, Luke Marris, Daniel Cownden, Colin Akerman, Douglas Tweed, Geoffrey Hinton The “credit assignment” problem The solution in artificial networks: backprop Credit assignment by backprop works well in practice and shows up in virtually all of the state-of-the-art supervised, unsupervised, and reinforcement learning algorithms. Why Isn’t Backprop “Biologically Plausible”? Why Isn’t Backprop “Biologically Plausible”? Neuroscience Evidence for Backprop in the Brain? A spectrum of credit assignment algorithms: A spectrum of credit assignment algorithms: A spectrum of credit assignment algorithms: How to convince a neuroscientist that the cortex is learning via [something like] backprop - To convince a machine learning researcher, an appeal to variance in gradient estimates might be enough. - But this is rarely enough to convince a neuroscientist. - So what lines of argument help? How to convince a neuroscientist that the cortex is learning via [something like] backprop - What do I mean by “something like backprop”?: - That learning is achieved across multiple layers by sending information from neurons closer to the output back to “earlier” layers to help compute their synaptic updates. How to convince a neuroscientist that the cortex is learning via [something like] backprop 1. Feedback connections in cortex are ubiquitous and modify the -
Predrnn: Recurrent Neural Networks for Predictive Learning Using Spatiotemporal Lstms
PredRNN: Recurrent Neural Networks for Predictive Learning using Spatiotemporal LSTMs Yunbo Wang Mingsheng Long∗ School of Software School of Software Tsinghua University Tsinghua University [email protected] [email protected] Jianmin Wang Zhifeng Gao Philip S. Yu School of Software School of Software School of Software Tsinghua University Tsinghua University Tsinghua University [email protected] [email protected] [email protected] Abstract The predictive learning of spatiotemporal sequences aims to generate future images by learning from the historical frames, where spatial appearances and temporal vari- ations are two crucial structures. This paper models these structures by presenting a predictive recurrent neural network (PredRNN). This architecture is enlightened by the idea that spatiotemporal predictive learning should memorize both spatial ap- pearances and temporal variations in a unified memory pool. Concretely, memory states are no longer constrained inside each LSTM unit. Instead, they are allowed to zigzag in two directions: across stacked RNN layers vertically and through all RNN states horizontally. The core of this network is a new Spatiotemporal LSTM (ST-LSTM) unit that extracts and memorizes spatial and temporal representations simultaneously. PredRNN achieves the state-of-the-art prediction performance on three video prediction datasets and is a more general framework, that can be easily extended to other predictive learning tasks by integrating with other architectures. 1 Introduction -
Almost Unsupervised Text to Speech and Automatic Speech Recognition
Almost Unsupervised Text to Speech and Automatic Speech Recognition Yi Ren * 1 Xu Tan * 2 Tao Qin 2 Sheng Zhao 3 Zhou Zhao 1 Tie-Yan Liu 2 Abstract 1. Introduction Text to speech (TTS) and automatic speech recognition (ASR) are two popular tasks in speech processing and have Text to speech (TTS) and automatic speech recog- attracted a lot of attention in recent years due to advances in nition (ASR) are two dual tasks in speech pro- deep learning. Nowadays, the state-of-the-art TTS and ASR cessing and both achieve impressive performance systems are mostly based on deep neural models and are all thanks to the recent advance in deep learning data-hungry, which brings challenges on many languages and large amount of aligned speech and text data. that are scarce of paired speech and text data. Therefore, However, the lack of aligned data poses a ma- a variety of techniques for low-resource and zero-resource jor practical problem for TTS and ASR on low- ASR and TTS have been proposed recently, including un- resource languages. In this paper, by leveraging supervised ASR (Yeh et al., 2019; Chen et al., 2018a; Liu the dual nature of the two tasks, we propose an et al., 2018; Chen et al., 2018b), low-resource ASR (Chuang- almost unsupervised learning method that only suwanich, 2016; Dalmia et al., 2018; Zhou et al., 2018), TTS leverages few hundreds of paired data and extra with minimal speaker data (Chen et al., 2019; Jia et al., 2018; unpaired data for TTS and ASR. -
Self-Supervised Learning
Self-Supervised Learning Andrew Zisserman Slides from: Carl Doersch, Ishan Misra, Andrew Owens, Carl Vondrick, Richard Zhang The ImageNet Challenge Story … 1000 categories • Training: 1000 images for each category • Testing: 100k images The ImageNet Challenge Story … strong supervision The ImageNet Challenge Story … outcomes Strong supervision: • Features from networks trained on ImageNet can be used for other visual tasks, e.g. detection, segmentation, action recognition, fine grained visual classification • To some extent, any visual task can be solved now by: 1. Construct a large-scale dataset labelled for that task 2. Specify a training loss and neural network architecture 3. Train the network and deploy • Are there alternatives to strong supervision for training? Self-Supervised learning …. Why Self-Supervision? 1. Expense of producing a new dataset for each new task 2. Some areas are supervision-starved, e.g. medical data, where it is hard to obtain annotation 3. Untapped/availability of vast numbers of unlabelled images/videos – Facebook: one billion images uploaded per day – 300 hours of video are uploaded to YouTube every minute 4. How infants may learn … Self-Supervised Learning The Scientist in the Crib: What Early Learning Tells Us About the Mind by Alison Gopnik, Andrew N. Meltzoff and Patricia K. Kuhl The Development of Embodied Cognition: Six Lessons from Babies by Linda Smith and Michael Gasser What is Self-Supervision? • A form of unsupervised learning where the data provides the supervision • In general, withhold some part of the data, and task the network with predicting it • The task defines a proxy loss, and the network is forced to learn what we really care about, e.g. -
Reinforcement Learning in Supervised Problem Domains
Technische Universität München Fakultät für Informatik Lehrstuhl VI – Echtzeitsysteme und Robotik reinforcement learning in supervised problem domains Thomas F. Rückstieß Vollständiger Abdruck der von der Fakultät für Informatik der Technischen Universität München zur Erlangung des akademischen Grades eines Doktors der Naturwissenschaften (Dr. rer. nat.) genehmigten Dissertation. Vorsitzender: Univ.-Prof. Dr. Daniel Cremers Prüfer der Dissertation 1. Univ.-Prof. Dr. Patrick van der Smagt 2. Univ.-Prof. Dr. Hans Jürgen Schmidhuber Die Dissertation wurde am 30. 06. 2015 bei der Technischen Universität München eingereicht und durch die Fakultät für Informatik am 18. 09. 2015 angenommen. Thomas Rückstieß: Reinforcement Learning in Supervised Problem Domains © 2015 email: [email protected] ABSTRACT Despite continuous advances in computing technology, today’s brute for- ce data processing approaches may not provide the necessary advantage to win the race against the ever-growing amount of data that can be wit- nessed over the last decades. In this thesis, we discuss novel methods and algorithms that are capable of directing attention to relevant details and analysing it in sequence to overcome the processing bottleneck and to keep up with this data explosion. In the first of three parts, a novel exploration technique for Policy Gradi- ent Reinforcement Learning is presented which replaces traditional ad- ditive random exploration with state-dependent exploration, exploring on a higher, more strategic level. We will show how this new exploration method converges faster and finds better global solutions than random exploration can. The second part of this thesis will introduce the concept of “data con- sumption” and discuss means to minimise it in supervised learning tasks by deriving classification as a sequential decision process and ma- king it accessible to Reinforcement Learning methods. -
Deep Learning Architectures for Sequence Processing
Speech and Language Processing. Daniel Jurafsky & James H. Martin. Copyright © 2021. All rights reserved. Draft of September 21, 2021. CHAPTER Deep Learning Architectures 9 for Sequence Processing Time will explain. Jane Austen, Persuasion Language is an inherently temporal phenomenon. Spoken language is a sequence of acoustic events over time, and we comprehend and produce both spoken and written language as a continuous input stream. The temporal nature of language is reflected in the metaphors we use; we talk of the flow of conversations, news feeds, and twitter streams, all of which emphasize that language is a sequence that unfolds in time. This temporal nature is reflected in some of the algorithms we use to process lan- guage. For example, the Viterbi algorithm applied to HMM part-of-speech tagging, proceeds through the input a word at a time, carrying forward information gleaned along the way. Yet other machine learning approaches, like those we’ve studied for sentiment analysis or other text classification tasks don’t have this temporal nature – they assume simultaneous access to all aspects of their input. The feedforward networks of Chapter 7 also assumed simultaneous access, al- though they also had a simple model for time. Recall that we applied feedforward networks to language modeling by having them look only at a fixed-size window of words, and then sliding this window over the input, making independent predictions along the way. Fig. 9.1, reproduced from Chapter 7, shows a neural language model with window size 3 predicting what word follows the input for all the. Subsequent words are predicted by sliding the window forward a word at a time. -
Infinite Variational Autoencoder for Semi-Supervised Learning
Infinite Variational Autoencoder for Semi-Supervised Learning M. Ehsan Abbasnejad Anthony Dick Anton van den Hengel The University of Adelaide {ehsan.abbasnejad, anthony.dick, anton.vandenhengel}@adelaide.edu.au Abstract with whatever labelled data is available to train a discrimi- native model for classification. This paper presents an infinite variational autoencoder We demonstrate that our infinite VAE outperforms both (VAE) whose capacity adapts to suit the input data. This the classical VAE and standard classification methods, par- is achieved using a mixture model where the mixing coef- ticularly when the number of available labelled samples is ficients are modeled by a Dirichlet process, allowing us to small. This is because the infinite VAE is able to more ac- integrate over the coefficients when performing inference. curately capture the distribution of the unlabelled data. It Critically, this then allows us to automatically vary the therefore provides a generative model that allows the dis- number of autoencoders in the mixture based on the data. criminative model, which is trained based on its output, to Experiments show the flexibility of our method, particularly be more effectively learnt using a small number of samples. for semi-supervised learning, where only a small number of The main contribution of this paper is twofold: (1) we training samples are available. provide a Bayesian non-parametric model for combining autoencoders, in particular variational autoencoders. This bridges the gap between non-parametric Bayesian meth- 1. Introduction ods and the deep neural networks; (2) we provide a semi- supervised learning approach that utilizes the infinite mix- The Variational Autoencoder (VAE) [18] is a newly in- ture of autoencoders learned by our model for prediction troduced tool for unsupervised learning of a distribution x x with from a small number of labeled examples. -
Unsupervised Speech Representation Learning Using Wavenet Autoencoders Jan Chorowski, Ron J
1 Unsupervised speech representation learning using WaveNet autoencoders Jan Chorowski, Ron J. Weiss, Samy Bengio, Aaron¨ van den Oord Abstract—We consider the task of unsupervised extraction speaker gender and identity, from phonetic content, properties of meaningful latent representations of speech by applying which are consistent with internal representations learned autoencoding neural networks to speech waveforms. The goal by speech recognizers [13], [14]. Such representations are is to learn a representation able to capture high level semantic content from the signal, e.g. phoneme identities, while being desired in several tasks, such as low resource automatic speech invariant to confounding low level details in the signal such as recognition (ASR), where only a small amount of labeled the underlying pitch contour or background noise. Since the training data is available. In such scenario, limited amounts learned representation is tuned to contain only phonetic content, of data may be sufficient to learn an acoustic model on the we resort to using a high capacity WaveNet decoder to infer representation discovered without supervision, but insufficient information discarded by the encoder from previous samples. Moreover, the behavior of autoencoder models depends on the to learn the acoustic model and a data representation in a fully kind of constraint that is applied to the latent representation. supervised manner [15], [16]. We compare three variants: a simple dimensionality reduction We focus on representations learned with autoencoders bottleneck, a Gaussian Variational Autoencoder (VAE), and a applied to raw waveforms and spectrogram features and discrete Vector Quantized VAE (VQ-VAE). We analyze the quality investigate the quality of learned representations on LibriSpeech of learned representations in terms of speaker independence, the ability to predict phonetic content, and the ability to accurately re- [17]. -
Machine Learning V/S Deep Learning
International Research Journal of Engineering and Technology (IRJET) e-ISSN: 2395-0056 Volume: 06 Issue: 02 | Feb 2019 www.irjet.net p-ISSN: 2395-0072 Machine Learning v/s Deep Learning Sachin Krishan Khanna Department of Computer Science Engineering, Students of Computer Science Engineering, Chandigarh Group of Colleges, PinCode: 140307, Mohali, India ---------------------------------------------------------------------------***--------------------------------------------------------------------------- ABSTRACT - This is research paper on a brief comparison and summary about the machine learning and deep learning. This comparison on these two learning techniques was done as there was lot of confusion about these two learning techniques. Nowadays these techniques are used widely in IT industry to make some projects or to solve problems or to maintain large amount of data. This paper includes the comparison of two techniques and will also tell about the future aspects of the learning techniques. Keywords: ML, DL, AI, Neural Networks, Supervised & Unsupervised learning, Algorithms. INTRODUCTION As the technology is getting advanced day by day, now we are trying to make a machine to work like a human so that we don’t have to make any effort to solve any problem or to do any heavy stuff. To make a machine work like a human, the machine need to learn how to do work, for this machine learning technique is used and deep learning is used to help a machine to solve a real-time problem. They both have algorithms which work on these issues. With the rapid growth of this IT sector, this industry needs speed, accuracy to meet their targets. With these learning algorithms industry can meet their requirements and these new techniques will provide industry a different way to solve problems. -
Comparative Analysis of Recurrent Neural Network Architectures for Reservoir Inflow Forecasting
water Article Comparative Analysis of Recurrent Neural Network Architectures for Reservoir Inflow Forecasting Halit Apaydin 1 , Hajar Feizi 2 , Mohammad Taghi Sattari 1,2,* , Muslume Sevba Colak 1 , Shahaboddin Shamshirband 3,4,* and Kwok-Wing Chau 5 1 Department of Agricultural Engineering, Faculty of Agriculture, Ankara University, Ankara 06110, Turkey; [email protected] (H.A.); [email protected] (M.S.C.) 2 Department of Water Engineering, Agriculture Faculty, University of Tabriz, Tabriz 51666, Iran; [email protected] 3 Department for Management of Science and Technology Development, Ton Duc Thang University, Ho Chi Minh City, Vietnam 4 Faculty of Information Technology, Ton Duc Thang University, Ho Chi Minh City, Vietnam 5 Department of Civil and Environmental Engineering, Hong Kong Polytechnic University, Hong Kong, China; [email protected] * Correspondence: [email protected] or [email protected] (M.T.S.); [email protected] (S.S.) Received: 1 April 2020; Accepted: 21 May 2020; Published: 24 May 2020 Abstract: Due to the stochastic nature and complexity of flow, as well as the existence of hydrological uncertainties, predicting streamflow in dam reservoirs, especially in semi-arid and arid areas, is essential for the optimal and timely use of surface water resources. In this research, daily streamflow to the Ermenek hydroelectric dam reservoir located in Turkey is simulated using deep recurrent neural network (RNN) architectures, including bidirectional long short-term memory (Bi-LSTM), gated recurrent unit (GRU), long short-term memory (LSTM), and simple recurrent neural networks (simple RNN). For this purpose, daily observational flow data are used during the period 2012–2018, and all models are coded in Python software programming language. -
Deep Learning and Neural Networks Module 4
Deep Learning and Neural Networks Module 4 Table of Contents Learning Outcomes ......................................................................................................................... 5 Review of AI Concepts ................................................................................................................... 6 Artificial Intelligence ............................................................................................................................ 6 Supervised and Unsupervised Learning ................................................................................................ 6 Artificial Neural Networks .................................................................................................................... 8 The Human Brain and the Neural Network ........................................................................................... 9 Machine Learning Vs. Neural Network ............................................................................................... 11 Machine Learning vs. Neural Network Comparison Table (Educba, 2019) .............................................. 12 Conclusion – Machine Learning vs. Neural Network ........................................................................... 13 Real-time Speech Translation ............................................................................................................. 14 Uses of a Translator App ................................................................................................................... -
Introduction Q-Learning and Variants
Introduction In this assignment, you will implement Q-learning using deep learning function approxima- tors in OpenAI Gym. You will work with the Atari game environments, and learn how to train a Q-network directly from pixel inputs. The goal is to understand and implement some of the techniques that were found to be important in practice to stabilize training and achieve better performance. As a side effect, we also expect you to get comfortable using Tensorflow or Keras to experiment with different architectures and different hyperparameter configurations and gain insight into the importance of these choices on final performance and learning behavior. Before starting your implementation, make sure that you have Tensorflow and the Atari environments correctly installed. For this assignment you may choose either Enduro (Enduro-v0) or Space Invaders (SpaceInvaders-v0). In spite of this, the observations from other Atari games have the same size so you can try to train your models in the other games too. Note that while the size of the observations is the same across games, the number of available actions may be different from game to game. Q-learning and variants Due to the state space complexity of Atari environments, we represent Q-functions using a p class of parametrized function approximators Q = fQw j w 2 R g, where p is the number of parameters. Remember that in the tabular setting, given a 4-tuple of sampled experience (s; a; r; s0), the vanilla Q-learning update is Q(s; a) := Q(s; a) + α r + γ max Q(s0; a0) − Q(s; a) ; (1) a02A where α 2 R is the learning rate.