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Fast and Robust Shortest Paths on Manifolds Learned from Data

arXiv.org Machine Learning

We propose a fast, simple and robust algorithm for computing shortest paths and distances on Riemannian manifolds learned from data. This amounts to solving a system of ordinary differential equations (ODEs) subject to boundary conditions. Here standard solvers perform poorly because they require well-behaved Jacobians of the ODE, and usually, manifolds learned from data imply unstable and ill-conditioned Jacobians. Instead, we propose a fixed-point iteration scheme for solving the ODE that avoids Jacobians. This enhances the stability of the solver, while reduces the computational cost. In experiments involving both Riemannian metric learning and deep generative models we demonstrate significant improvements in speed and stability over both general-purpose state-of-the-art solvers as well as over specialized solvers.


Visual Imitation Learning with Recurrent Siamese Networks

arXiv.org Machine Learning

People solve the difficult problem of understanding the salient features of both observations of others and the relationship to their own state when learning to imitate specific tasks. In this work, we train a comparator network which is used to compute distances between motions. Given a desired motion the comparator can provide a reward signal to the agent via the distance between the desired motion and the agent's motion. We train an RNN-based comparator model to compute distances in space and time between motion clips while training an RL policy to minimize this distance. Furthermore, we examine a challenging form of this problem where a single \demonstrationText is provided for a given task. We demonstrate our approach in the setting of deep learning based control for physical simulation of humanoid walking in both 2D with $10$ degrees of freedom (DoF) and 3D with $38$ DoF.


Efficient Representation Learning Using Random Walks for Dynamic Graphs

arXiv.org Machine Learning

An important part of many machine learning workflows on graphs is vertex representation learning, i.e., learning a low-dimensional vector representation for each vertex in the graph. Recently, several powerful techniques for unsupervised representation learning have been demonstrated to give the state-of-the-art performance in downstream tasks such as vertex classification and edge prediction. These techniques rely on random walks performed on the graph in order to capture its structural properties. These structural properties are then encoded in the vector representation space. However, most contemporary representation learning methods only apply to static graphs while real-world graphs are often dynamic and change over time. Static representation learning methods are not able to update the vector representations when the graph changes; therefore, they must re-generate the vector representations on an updated static snapshot of the graph regardless of the extent of the change in the graph. In this work, we propose computationally efficient algorithms for vertex representation learning that extend random walk based methods to dynamic graphs. The computation complexity of our algorithms depends upon the extent and rate of changes (the number of edges changed per update) and on the density of the graph. We empirically evaluate our algorithms on real world datasets for downstream machine learning tasks of multi-class and multi-label vertex classification. The results show that our algorithms can achieve competitive results to the state-of-the-art methods while being computationally efficient.


Rank Pruning for Dominance Queries in CP-Nets

Journal of Artificial Intelligence Research

Conditional preference networks (CP-nets) are a graphical representation of a person's (conditional) preferences over a set of discrete features. In this paper, we introduce a novel method of quantifying preference for any given outcome based on a CP-net representation of a user's preferences. We demonstrate that these values are useful for reasoning about user preferences. In particular, they allow us to order (any subset of) the possible outcomes in accordance with the user's preferences. Further, these values can be used to improve the efficiency of outcome dominance testing. That is, given a pair of outcomes, we can determine which the user prefers more efficiently. Through experimental results, we show that this method is more effective than existing techniques for improving dominance testing efficiency. We show that the above results also hold for CP-nets that express indifference between variable values.


Driver Distraction Identification with an Ensemble of Convolutional Neural Networks

arXiv.org Machine Learning

The World Health Organization (WHO) reported 1.25 million deaths yearly due to road traffic accidents worldwide and the number has been continuously increasing over the last few years. Nearly fifth of these accidents are caused by distracted drivers. Existing work of distracted driver detection is concerned with a small set of distractions (mostly, cell phone usage). Unreliable ad-hoc methods are often used.In this paper, we present the first publicly available dataset for driver distraction identification with more distraction postures than existing alternatives. In addition, we propose a reliable deep learning-based solution that achieves a 90% accuracy. The system consists of a genetically-weighted ensemble of convolutional neural networks, we show that a weighted ensemble of classifiers using a genetic algorithm yields in a better classification confidence. We also study the effect of different visual elements in distraction detection by means of face and hand localizations, and skin segmentation. Finally, we present a thinned version of our ensemble that could achieve 84.64% classification accuracy and operate in a real-time environment.


Optimal Finite-Sum Smooth Non-Convex Optimization with SARAH

arXiv.org Machine Learning

The total complexity (measured as the total number of gradient computations) of a stochastic first-order optimization algorithm that finds a first-order stationary point of a finite-sum smooth nonconvex objective function $F(w)=\frac{1}{n} \sum_{i=1}^n f_i(w)$ has been proven to be at least $\Omega(\sqrt{n}/\epsilon)$ where $\epsilon$ denotes the attained accuracy $\mathbb{E}[ \|\nabla F(\tilde{w})\|^2] \leq \epsilon$ for the outputted approximation $\tilde{w}$ (Fang et al.,2018). This paper is the first to show that this lower bound is tight for the class of variance reduction methods which only assume the Lipschitz continuous gradient assumption. We prove this complexity result for a slightly modified version of the SARAH algorithm in (Nguyen et al.,2017a;b) - showing that SARAH is optimal and dominates all existing results. For convex optimization, we propose SARAH++ with sublinear convergence for general convex and linear convergence for strongly convex problems; and we provide a practical version for which numerical experiments on various datasets show an improved performance.


The Limits of Morality in Strategic Games

arXiv.org Artificial Intelligence

A coalition is blameable for an outcome if the coalition had a strategy to prevent it. It has been previously suggested that the cost of prevention, or the cost of sacrifice, can be used to measure the degree of blameworthiness. The paper adopts this approach and proposes a modal logical system for reasoning about the degree of blameworthiness. The main technical result is a completeness theorem for the proposed system.


A GFML-based Robot Agent for Human and Machine Cooperative Learning on Game of Go

arXiv.org Artificial Intelligence

This paper applies a genetic algorithm and fuzzy markup language to construct a human and smart machine cooperative learning system on game of Go. The genetic fuzzy markup language (GFML)-based Robot Agent can work on various kinds of robots, including Palro, Pepper, and TMUs robots. We use the parameters of FAIR open source Darkforest and OpenGo AI bots to construct the knowledge base of Open Go Darkforest (OGD) cloud platform for student learning on the Internet. In addition, we adopt the data from AlphaGo Master sixty online games as the training data to construct the knowledge base and rule base of the co-learning system. First, the Darkforest predicts the win rate based on various simulation numbers and matching rates for each game on OGD platform, then the win rate of OpenGo is as the final desired output. The experimental results show that the proposed approach can improve knowledge base and rule base of the prediction ability based on Darkforest and OpenGo AI bot with various simulation numbers.


Innovative ideas to address global challenges

The Japan Times

As a forerunner facing various social challenges, including addressing the aging population, as well as environmental and energy issues, Japan is poised to find solutions and share them with other countries that are also expected to be confronted with these complex problems. Through hosting the upcoming G20 summit in Osaka in June, the country will promote further cooperation among all relevant stakeholders, both government and non-governmental, toward a future society that realizes both economic growth and solutions for such issues. The annual meeting of the World Economic Forum (WEF) in Davos, Switzerland, will be a timely occasion for world leaders to address these growing challenges as the conference aims to delve into the topics to "shape a new framework for global cooperation," preparing for the arrival of "Globalization 4.0" driven by the "Fourth Industrial Revolution." Assuming the G20 presidency immediately after the Buenos Aires summit in December, Prime Minister Shinzo Abe stated Japan would seek to realize a "human-centered future society," promoting discussions in cross-cutting areas. "Japan is determined to lead global economic growth by promoting free trade and innovation, achieving both economic growth and reduction of disparities, and contributing to the development agenda and other global issues with the SDGs (United Nations Sustainable Development Goals) at its core," Abe said. "In addition, we will lead discussions on the supply of global commons for realizing global growth such as quality infrastructure and global health," he continued. "We will exert strong leadership in discussions aimed toward resolving global issues such as climate change and ocean plastic waste."


Microsoft lays AI sensors for smart farming, cutting-edge healthcare in India - Weekly Voice

#artificialintelligence

The aim is clear: To help the community digitally record information to cut costs and increase yields -- with just a smartphone in their hands as AI leveraged Cloud computing to make sense of the data for farmers. India has now embarked on a journey to bring AI sensors into the fields. For Anant Maheshwari, the company's India President, Microsoft has begun empowering small-holder farmers in India to increase their income through higher crop yield and greater price control. "We are working with farmers, state governments, the Ministry of Electronics and Information Technology (MeitY) and the Ministry of Agriculture and Farmers Welfare to create an ecosystem for AI into farming," Maheshwari told IANS. In some villages in Telangana, Maharashtra and Madhya Pradesh, farmers are receiving automated voice calls that tell them whether their cotton crops are at risk of a pest attack, based on weather conditions and crop stage.