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Now the Computer Can Argue With You

WIRED

"Fighting technology means fighting human ingenuity," an IBM software program admonished Israeli debating champion Dan Zafrir in San Francisco Monday. The program, dubbed Project Debater, and Zafrir, were debating the value of telemedicine, but the point could also apply to the future of the technology itself. Software that processes speech and language has improved enough to do more than tell you the weather forecast. You may not be ready for machines capable of conversation or arguing, but tech companies are working to find uses for them. IBM's demo of Project Debater comes a month after Google released audio of a bot called Duplex booking restaurants and haircuts over the phone.


Flying cars: why haven't they taken off yet?

The Guardian

In 1940, Henry Ford said: "Mark my words – a combination aeroplane and motor car is coming." With flying taxis apparently on the way, it looks like he was right, but what a wait. Eight decades years later, "dude, where's my flying car?" is shorthand for any stuff "they" promised us that we haven't got. We have always wanted to fly, so, as soon as cars came on to the scene, we wanted those to fly too. Early blueprints for the US interstate highway grid even had adjacent runways ready for flying cars.


The rise of the "Automacene": How robots will define the next epoch in human history

#artificialintelligence

I've always had a close relationship with robots -- even a fondness for them. When I was a kid I had a Baby Alive doll, mass-produced in the 1970s by Kenner. The baby ate through its battery-operated mouth and subsequently pooped, a ridiculously simple simulation of the real-life care of a newborn. In the wake of an avalanche of news on the ethical implications of technology -- whether that's Google bowing out of the military's Project Maven or a report questioning whether it's emotionally healthy to have sex with robots (it's probably not) -- I connected the trail of my own attachment with AIs and their physical counterparts, robots. Throughout my own career, I've thought a lot about robots replacing jobs.


Fast, Robust, and Versatile Event Detection through HMM Belief State Gradient Measures

arXiv.org Artificial Intelligence

Event detection is a critical feature in data-driven systems as it assists with the identification of nominal and anomalous behavior. Event detection is increasingly relevant in robotics as robots operate with greater autonomy in increasingly unstructured environments. In this work, we present an accurate, robust, fast, and versatile measure for skill and anomaly identification. A theoretical proof establishes the link between the derivative of the log-likelihood of the HMM filtered belief state and the latest emission probabilities. The key insight is the inverse relationship in which gradient analysis is used for skill and anomaly identification. Our measure showed better performance across all metrics than related state-of-the art works. The result is broadly applicable to domains that use HMMs for event detection.


Large-Scale Stochastic Sampling from the Probability Simplex

arXiv.org Machine Learning

Emily B. Fox Department of Statistics University of Washington Stochastic gradient Markov chain Monte Carlo (SGMCMC) has become a popular method for scalable Bayesian inference. These methods are based on sampling a discrete-time approximation to a continuous time process, such as the Langevin diffusion. When applied to distributions defined on a constrained space, such as the simplex, the time-discretisation error can dominate when we are near the boundary of the space. We demonstrate that while current SGMCMC methods for the simplex perform well in certain cases, they struggle with sparse simplex spaces; when many of the components are close to zero. However, most popular large-scale applications of Bayesian inference on simplex spaces, such as network or topic models, are sparse. We argue that this poor performance is due to the biases of SGMCMC caused by the discretization error. To get around this, we propose the stochastic CIR process, which removes all discretization error and we prove that samples from the stochastic CIR process are asymptotically unbiased. Use of the stochastic CIR process within a SGMCMC algorithm is shown to give substantially better performance for a topic model and a Dirichlet process mixture model than existing SGMCMC approaches.


Approximation Strategies for Incomplete MaxSAT

arXiv.org Artificial Intelligence

Incomplete MaxSAT solving aims to quickly find a solution that attempts to minimize the sum of the weights of the unsatisfied soft clauses without providing any optimality guarantees. In this paper, we propose two approximation strategies for improving incomplete MaxSAT solving. In one of the strategies, we cluster the weights and approximate them with a representative weight. In another strategy, we break up the problem of minimizing the sum of weights of unsatisfiable clauses into multiple minimization subproblems. Experimental results show that approximation strategies can be used to find better solutions than the best incomplete solvers in the MaxSAT Evaluation 2017.


A Latent Variable Approach to Gaussian Process Modeling with Qualitative and Quantitative Factors

arXiv.org Machine Learning

Computer simulations often involve both qualitative and numerical inputs. Existing Gaussian process (GP) methods for handling this mainly assume a different response surface for each combination of levels of the qualitative factors and relate them via a multiresponse cross-covariance matrix. We introduce a substantially different approach that maps each qualitative factor to an underlying numerical latent variable (LV), with the mapped value for each level estimated similarly to the covariance lengthscale parameters. This provides a parsimonious GP parameterization that treats qualitative factors the same as numerical variables and views them as effecting the response via similar physical mechanisms. This has strong physical justification, as the effects of a qualitative factor in any physics-based simulation model must always be due to some underlying numerical variables. Even when the underlying variables are many, sufficient dimension reduction arguments imply that their effects can be represented by a low-dimensional LV. This conjecture is supported by the superior predictive performance observed across a variety of examples. Moreover, the mapped LVs provide substantial insight into the nature and effects of the qualitative factors.


Online Linear Quadratic Control

arXiv.org Machine Learning

We study the problem of controlling linear time-invariant systems with known noisy dynamics and adversarially chosen quadratic losses. We present the first efficient online learning algorithms in this setting that guarantee $O(\sqrt{T})$ regret under mild assumptions, where $T$ is the time horizon. Our algorithms rely on a novel SDP relaxation for the steady-state distribution of the system. Crucially, and in contrast to previously proposed relaxations, the feasible solutions of our SDP all correspond to "strongly stable" policies that mix exponentially fast to a steady state.


Learning Equations for Extrapolation and Control

arXiv.org Machine Learning

We present an approach to identify concise equations from data using a shallow neural network approach. In contrast to ordinary black-box regression, this approach allows understanding functional relations and generalizing them from observed data to unseen parts of the parameter space. We show how to extend the class of learnable equations for a recently proposed equation learning network to include divisions, and we improve the learning and model selection strategy to be useful for challenging real-world data. For systems governed by analytical expressions, our method can in many cases identify the true underlying equation and extrapolate to unseen domains. We demonstrate its effectiveness by experiments on a cart-pendulum system, where only 2 random rollouts are required to learn the forward dynamics and successfully achieve the swing-up task.


Restricted Boltzmann Machines: Introduction and Review

arXiv.org Machine Learning

The restricted Boltzmann machine is a network of stochastic units with undirected interactions between pairs of visible and hidden units. This model was popularized as a building block of deep learning architectures and has continued to play an important role in applied and theoretical machine learning. Restricted Boltzmann machines carry a rich structure, with connections to geometry, applied algebra, probability, statistics, machine learning, and other areas. The analysis of these models is attractive in its own right and also as a platform to combine and generalize mathematical tools for graphical models with hidden variables. This article gives an introduction to the mathematical analysis of restricted Boltzmann machines, reviews recent results on the geometry of the sets of probability distributions representable by these models, and suggests a few directions for further investigation.