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 Deep Learning


This Man Is the Godfather the AI Community Wants to Forget

#artificialintelligence

Many of the biggest names in the technology industry are consumed with developing an artificial general intelligence, or AGI. Unlike today's leading artificial intelligence software, an AGI wouldn't need flesh-and-blood trainers to figure out how to translate English to Mandarin or spot tumors in an X-ray. In theory, it would have some measure of independence from its creators, solve complex, novel problems on its own, and herald an era in which humankind is no longer superior to machines. The consensus among our pitiful fleshbrains is that if humans ever manage to create an AGI, it'll arise in Mountain View, Calif., Beijing, or Moscow. All three cities are near world-class AI research universities and are home to companies that have pumped billions into the AGI race. There exists, however, a chance that the breakthrough will come from the Swiss city of Lugano. The picturesque slice of Switzerland's southern tip is home to about 60,000 people, including a computer scientist named Jรผrgen Schmidhuber. He's a professor, a researcher, and the co-founder of a 25-employee AI startup called Nnaisense.


Omega: An Architecture for AI Unification

arXiv.org Artificial Intelligence

We introduce the open-ended, modular, self-improving Omega AI unification architecture which is a refinement of Solomonoff's Alpha architecture, as considered from first principles. The architecture embodies several crucial principles of general intelligence including diversity of representations, diversity of data types, integrated memory, modularity, and higher-order cognition. We retain the basic design of a fundamental algorithmic substrate called an "AI kernel" for problem solving and basic cognitive functions like memory, and a larger, modular architecture that re-uses the kernel in many ways. Omega includes eight representation languages and six classes of neural networks, which are briefly introduced. The architecture is intended to initially address data science automation, hence it includes many problem solving methods for statistical tasks. We review the broad software architecture, higher-order cognition, self-improvement, modular neural architectures, intelligent agents, the process and memory hierarchy, hardware abstraction, peer-to-peer computing, and data abstraction facility.


Towards Explaining Anomalies: A Deep Taylor Decomposition of One-Class Models

arXiv.org Machine Learning

One such application is intrusion detection in computer systems, where data points are typically digital messages transmitted over a network, and messages that are detected as outliers are considered likely to carry a threat [13, 17]. Another application is obstacle detection in autonomous car driving [18]. The ability to detect outliers is also important in scientific applications, where points detected as such are intrinsically more interesting than inliers, and should therefore be given more attention [59, 28]. A number of techniques can be used for outlier detection [12, 21, 36, 41, 51]. In practice, it is not only important to be able to detect outliers and inliers with high accuracy, one would also like to be able to explain why a machine learning model considers a sample as inlier or outlier. An interpretable explanatory feedback can indeed be used by a human operator for appropriate decision making. The data point could either be considered as benign and possibly incorporated to the dataset, or appropriate action might be taken. The problem of outlier explanation is shown schematically in Figure 1.


Conversational Analysis using Utterance-level Attention-based Bidirectional Recurrent Neural Networks

arXiv.org Artificial Intelligence

Recent approaches for dialogue act recognition have shown that context from preceding utterances is important to classify the subsequent one. It was shown that the performance improves rapidly when the context is taken into account. We propose an utterance-level attention-based bidirectional recurrent neural network (Utt-Att-BiRNN) model to analyze the importance of preceding utterances to classify the current one. In our setup, the BiRNN is given the input set of current and preceding utterances. Our model outperforms previous models that use only preceding utterances as context on the used corpus. Another contribution of the article is to discover the amount of information in each utterance to classify the subsequent one and to show that context-based learning not only improves the performance but also achieves higher confidence in the classification. We use character- and word-level features to represent the utterances. The results are presented for character and word feature representations and as an ensemble model of both representations. We found that when classifying short utterances, the closest preceding utterances contributes to a higher degree.


Constructing Narrative Event Evolutionary Graph for Script Event Prediction

arXiv.org Artificial Intelligence

Script event prediction requires a model to predict the subsequent event given an existing event context. Previous models based on event pairs or event chains cannot make full use of dense event connections, which may limit their capability of event prediction. To remedy this, we propose constructing an event graph to better utilize the event network information for script event prediction. In particular, we first extract narrative event chains from large quantities of news corpus, and then construct a narrative event evolutionary graph (NEEG) based on the extracted chains. NEEG can be seen as a knowledge base that describes event evolutionary principles and patterns. To solve the inference problem on NEEG, we present a scaled graph neural network (SGNN) to model event interactions and learn better event representations. Instead of computing the representations on the whole graph, SGNN processes only the concerned nodes each time, which makes our model feasible to large-scale graphs. By comparing the similarity between input context event representations and candidate event representations, we can choose the most reasonable subsequent event. Experimental results on widely used New York Times corpus demonstrate that our model significantly outperforms state-of-the-art baseline methods, by using standard multiple choice narrative cloze evaluation.


FollowNet: Robot Navigation by Following Natural Language Directions with Deep Reinforcement Learning

arXiv.org Artificial Intelligence

Understanding and following directions provided by humans can enable robots to navigate effectively in unknown situations. We present FollowNet, an end-to-end differentiable neural architecture for learning multi-modal navigation policies. FollowNet maps natural language instructions as well as visual and depth inputs to locomotion primitives. FollowNet processes instructions using an attention mechanism conditioned on its visual and depth input to focus on the relevant parts of the command while performing the navigation task. Deep reinforcement learning (RL) a sparse reward learns simultaneously the state representation, the attention function, and control policies. We evaluate our agent on a dataset of complex natural language directions that guide the agent through a rich and realistic dataset of simulated homes. We show that the FollowNet agent learns to execute previously unseen instructions described with a similar vocabulary, and successfully navigates along paths not encountered during training. The agent shows 30% improvement over a baseline model without the attention mechanism, with 52% success rate at novel instructions.


A Spline Theory of Deep Networks (Extended Version)

arXiv.org Machine Learning

We build a rigorous bridge between deep networks (DNs) and approximation theory via spline functions and operators. Our key result is that a large class of DNs can be written as a composition of max-affine spline operators (MASOs), which provide a powerful portal through which to view and analyze their inner workings. For instance, conditioned on the input signal, the output of a MASO DN can be written as a simple affine transformation of the input. This implies that a DN constructs a set of signal-dependent, class-specific templates against which the signal is compared via a simple inner product; we explore the links to the classical theory of optimal classification via matched filters and the effects of data memorization. Going further, we propose a simple penalty term that can be added to the cost function of any DN learning algorithm to force the templates to be orthogonal with each other; this leads to significantly improved classifi- cation performance and reduced overfitting with no change to the DN architecture. The spline partition of the input signal space that is implicitly induced by a MASO directly links DNs to the theory of vector quantization (VQ) and K-means clustering, which opens up new geometric avenue to study how DNs organize signals in a hierarchical fashion. To validate the utility of the VQ interpretation, we develop and validate a new distance metric for signals and images that quantifies the difference between their VQ encodings. (This paper is a significantly expanded version of a paper with the same title that will appear at ICML 2018.)


Joint Classification and Prediction CNN Framework for Automatic Sleep Stage Classification

arXiv.org Machine Learning

Sleep staging plays an important role in assessment and treatment of sleep issues. This work proposes a joint classification-and-prediction framework based on convolutional neural networks (CNNs) for automatic sleep staging, and, subsequently, introduces a simple yet efficient CNN architecture to power the framework. Given a single input epoch, the framework jointly determines its label (classification) and those of its neighboring epochs in the contextual output (prediction). While the proposed framework is orthogonal to the widely adopted classification schemes, which takes one or multiple epochs as a contextual input and produces a single classification decision on the target epoch, we demonstrate its advantages in different ways. First, it leverages the dependency among consecutive sleep epochs while surpassing the problems experienced with the common classification schemes. Second, even with a single model, the framework effortlessly produces multiple decisions as in ensemble-of-models methods which are essential in obtaining a good performance. Probabilistic aggregation techniques are then proposed to leverage the availability of multiple decisions. We demonstrate good performance on the Montreal Archive of Sleep Studies (MASS) dataset consisting 200 subjects with an average accuracy of 83.6%. We also show that the proposed framework not only is superior to the baselines based on the common classification schemes but also outperforms existing deep-learning approaches. To our knowledge, this is the first work going beyond the standard single-output classification to consider neural networks with multiple outputs for automatic sleep staging. This framework could provide avenues for further studies of different neural-network architectures for this problem.


Regularization Learning Networks

arXiv.org Machine Learning

Despite their impressive performance, Deep Neural Networks (DNNs) typically underperform Gradient Boosting Trees (GBTs) on many tabular-dataset learning tasks. We propose that applying a different regularization coefficient to each weight might boost the performance of DNNs by allowing them to make more use of the more relevant inputs. However, this will lead to an intractable number of hyperparameters. Here, we introduce Regularization Learning Networks (RLNs), which overcome this challenge by introducing an efficient hyperparameter tuning scheme that minimizes a new Counterfactual Loss. Our results show that RLNs significantly improve DNNs on tabular datasets, and achieve comparable results to GBTs, with the best performance achieved with an ensemble that combines GBTs and RLNs. RLNs produce extremely sparse networks, eliminating up to 99.8% of the network edges and 82% of the input features, thus providing more interpretable models and reveal the importance that the network assigns to different inputs. RLNs could efficiently learn a single network in datasets that comprise both tabular and unstructured data, such as in the setting of medical imaging accompanied by electronic health records.


Multi-task Learning for Macromolecule Classification, Segmentation and Coarse Structural Recovery in Cryo-Tomography

arXiv.org Machine Learning

Cellular Electron Cryo-Tomography (CECT) is a powerful 3D imaging tool for studying the native structure and organization of macromolecules inside single cells. For systematic recognition and recovery of macromolecular structures captured by CECT, methods for several important tasks such as subtomogram classification and semantic segmentation have been developed. However, the recognition and recovery of macromolecular structures are still very difficult due to high molecular structural diversity, crowding molecular environment, and the imaging limitations of CECT. In this paper, we propose a novel multi-task 3D convolutional neural network model for simultaneous classification, segmentation, and coarse structural recovery of macromolecules of interest in subtomograms. In our model, the learned image features of one task are shared and thereby mutually reinforce the learning of other tasks. Evaluated on realistically simulated and experimental CECT data, our multi-task learning model outperformed all single-task learning methods for classification and segmentation. In addition, we demonstrate that our model can generalize to discover, segment and recover novel structures that do not exist in the training data.