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Linear Satisfiability Preserving Assignments

Journal of Artificial Intelligence Research

In this paper, we study several classes of satisfiability preserving assignments to the constraint satisfaction problem (CSP). In particular, we consider fixable, autark and satisfying assignments. Since it is in general NP-hard to find a nontrivial (i.e., nonempty) satisfiability preserving assignment, we introduce linear satisfiability preserving assignments, which are defined by polyhedral cones in an associated vector space. The vector space is obtained by the identification, introduced by Kullmann, of assignments with real vectors. We consider arbitrary polyhedral cones, where only restricted classes of cones for autark assignments are considered in the literature. We reveal that cones in certain classes are maximal as a convex subset of the set of the associated vectors, which can be regarded as extensions of Kullmann's results for autark assignments of CNFs. As algorithmic results, we present a pseudo-polynomial time algorithm that computes a linear fixable assignment for a given integer linear system, which implies the well known pseudo-polynomial solvability for integer linear systems such as two-variable-per-inequality (TVPI), Horn and q-Horn systems.


Optimal Stochastic Package Delivery Planning with Deadline: A Cardinality Minimization in Routing

arXiv.org Artificial Intelligence

Vehicle Routing Problem with Private fleet and common Carrier (VRPPC) has been proposed to help a supplier manage package delivery services from a single depot to multiple customers. Most of the existing VRPPC works consider deterministic parameters which may not be practical and uncertainty has to be taken into account. In this paper, we propose the Optimal Stochastic Delivery Planning with Deadline (ODPD) to help a supplier plan and optimize the package delivery. The aim of ODPD is to service all customers within a given deadline while considering the randomness in customer demands and traveling time. We formulate the ODPD as a stochastic integer programming, and use the cardinality minimization approach for calculating the deadline violation probability. To accelerate computation, the L-shaped decomposition method is adopted. We conduct extensive performance evaluation based on real customer locations and traveling time from Google Map.


Semi-Analytic Resampling in Lasso

arXiv.org Machine Learning

An approximate method for conducting resampling in Lasso, the $\ell_1$ penalized linear regression, in a semi-analytic manner is developed, whereby the average over the resampled datasets is directly computed without repeated numerical sampling, thus enabling an inference free of the statistical fluctuations due to sampling finiteness, as well as a significant reduction of computational time. The proposed method is employed to implement bootstrapped Lasso (Bolasso) and stability selection, both of which are variable selection methods using resampling in conjunction with Lasso, and it resolves their disadvantage regarding computational cost. To examine approximation accuracy and efficiency, numerical experiments were carried out using simulated datasets. Moreover, an application to a real-world dataset, the wine quality dataset, is presented. To process such real-world datasets, an objective criterion for determining the relevance of selected variables is also introduced by the addition of noise variables and resampling.


Cognitive Radar Antenna Selection via Deep Learning

arXiv.org Machine Learning

Direction of arrival (DoA) estimation of targets improves with the number of elements employed by a phased array radar antenna. Since larger arrays have high associated cost, area and computational load, there is recent interest in thinning the antenna arrays without loss of far-field DoA accuracy. In this context, a cognitive radar may deploy a full array and then select an optimal subarray to transmit and receive the signals in response to changes in the target environment. Prior works have used optimization and greedy search methods to pick the best subarrays cognitively. In this paper, we leverage deep learning to address the antenna selection problem. Specifically, we construct a convolutional neural network (CNN) as a multi-class classification framework where each class designates a different subarray. The proposed network determines a new array every time data is received by the radar, thereby making antenna selection a cognitive operation. Our numerical experiments show that the proposed CNN structure outperforms existing random thinning and other machine learning approaches.


Scalable kernel-based variable selection with sparsistency

arXiv.org Machine Learning

Variable selection is central to high-dimensional data analysis, and various algorithms have been developed. Ideally, a variable selection algorithm shall be flexible, scalable, and with theoretical guarantee, yet most existing algorithms cannot attain these properties at the same time. In this article, a three-step variable selection algorithm is developed, involving kernel-based estimation of the regression function and its gradient functions as well as a hard thresholding. Its key advantage is that it assumes no explicit model assumption, admits general predictor effects, allows for scalable computation, and attains desirable asymptotic sparsistency. The proposed algorithm can be adapted to any reproducing kernel Hilbert space (RKHS) with different kernel functions, and can be extended to interaction selection with slight modification. Its computational cost is only linear in the data dimension, and can be further improved through parallel computing. The sparsistency of the proposed algorithm is established for general RKHS under mild conditions, including linear and Gaussian kernels as special cases. Its effectiveness is also supported by a variety of simulated and real examples.


Real-Time Bidding with Multi-Agent Reinforcement Learning in Display Advertising

arXiv.org Artificial Intelligence

Real-time advertising allows advertisers to bid for each impression for a visiting user. To optimize a specific goal such as maximizing the revenue led by ad placements, advertisers not only need to estimate the relevance between the ads and user's interests, but most importantly require a strategic response with respect to other advertisers bidding in the market. In this paper, we formulate bidding optimization with multi-agent reinforcement learning. To deal with a large number of advertisers, we propose a clustering method and assign each cluster with a strategic bidding agent. A practical Distributed Coordinated Multi-Agent Bidding (DCMAB) has been proposed and implemented to balance the tradeoff between the competition and cooperation among advertisers. The empirical study on our industry-scaled real-world data has demonstrated the effectiveness of our modeling methods. Our results show that a cluster based bidding would largely outperform single-agent and bandit approaches, and the coordinated bidding achieves better overall objectives than the purely self-interested bidding agents.


AI spots legal issues in contracts better than top lawyers

Daily Mail - Science & tech

Artificial intelligence has beaten top lawyers for the first time in a competition to make sense of legal contracts. Researchers found that AI was 10 per cent more accurate than humans in spotting key legal issues with business contracts - an everyday task for most lawyers. The news will stoke fears over the threat AI poses to many jobs, with robots expected to replace 300 million workers worldwide by 2030. Artificial intelligence has beaten lawyers for the first time in a competition to make sense of legal contracts. The contract-reviewing algorithm was created by legal AI platform LawGeex, which has teams based in both New York City and Tel Aviv, Israel.


Artificial Intelligence & Blockchain in Medicine Will Save Millions of People from Mistaken Diagnoses NewsBTC

#artificialintelligence

Skychain Global, for the first time in Russia, has successfully conducted a test of the artificial intelligence system for medical diagnostics, comparing the number of errors committed by the living doctors. This infrastructure blockchain project is aimed at helping doctors and patients have accurate diagnoses. Interestingly, this is the first ever test of its kind to be conducted in Russia. An infrastructure blockchain project, Skychain is dedicated to providing an infrastructure to radically increase the efficiency of healthcare AI development and training. There is no denying the fact that the field of medical sciences has experienced significant progress over the years.


China Startup Funding Overtakes USA

#artificialintelligence

The competition between China and the US in AI development is tricky to quantify. While we do have some hard numbers, even they are open to interpretation. The latest comes from technology analysts CB Insights, which reports that China has overtaken the US in the funding of AI startups. The country accounted for 48 percent of the world's total AI startup funding in 2017, compared to 38 percent for the US. The bottom line is that China is ahead when it comes to the dollar value of AI startup funding, which CB Insights says shows the country is "aggressively executing a thoroughly-designed vision for AI."


AI Beats Dermatologists in Diagnosing Nail Fungus

IEEE Spectrum Robotics

It's still relatively rare for artificial intelligence to deliver a crushing victory over human physicians in a head-to-head test of medical expertise. But a deep neural network approach managed to beat 42 dermatology experts in diagnosing a common nail fungus that affects about 35 million Americans each year. The latest successful demonstration of AI's capabilities in the medical field relied heavily upon a team of South Korean researchers putting together a huge dataset of almost 50,000 images of toenails and fingernails. That large amount of data used to train the deep neural networks on recognizing cases of onychomycosis--a common fungal infection that can make nails discolored and brittle--provided the crucial edge that enabled deep learning to outperform medical experts. "This study was the first to show that AI has overwhelmed the specialists," says Seung Seog Han, a dermatologist and clinician at I Dermatology in Seoul, South Korea.