The Panel Vector Autoregressive (PVAR) model is a popular tool for macroeconomic forecasting and structural analysis in multi-country applications since it allows for spillovers between countries in a very flexible fashion. However, this flexibility means that the number of parameters to be estimated can be enormous leading to over-parameterization concerns. Bayesian global-local shrinkage priors, such as the Horseshoe prior used in this paper, can overcome these concerns, but they require the use of Markov Chain Monte Carlo (MCMC) methods rendering them computationally infeasible in high dimensions. In this paper, we develop computationally efficient Bayesian methods for estimating PVARs using an integrated rotated Gaussian approximation (IRGA). This exploits the fact that whereas own country information is often important in PVARs, information on other countries is often unimportant. Using an IRGA, we split the the posterior into two parts: one involving own country coefficients, the other involving other country coefficients. Fast methods such as approximate message passing or variational Bayes can be used on the latter and, conditional on these, the former are estimated with precision using MCMC methods. In a forecasting exercise involving PVARs with up to $18$ variables for each of $38$ countries, we demonstrate that our methods produce good forecasts quickly.

In this paper we investigate how gradient-based algorithms such as gradient descent, (multi-pass) stochastic gradient descent, its persistent variant, and the Langevin algorithm navigate non-convex losslandscapes and which of them is able to reach the best generalization error at limited sample complexity. We consider the loss landscape of the high-dimensional phase retrieval problem as a prototypical highly non-convex example. We observe that for phase retrieval the stochastic variants of gradient descent are able to reach perfect generalization for regions of control parameters where the gradient descent algorithm is not. We apply dynamical mean-field theory from statistical physics to characterize analytically the full trajectories of these algorithms in their continuous-time limit, with a warm start, and for large system sizes. We further unveil several intriguing properties of the landscape and the algorithms such as that the gradient descent can obtain better generalization properties from less informed initializations.

Welcome to the fourth edition of the AI Index Report. This year we significantly expanded the amount of data available in the report, worked with a broader set of external organizations to calibrate our data, and deepened our connections with the Stanford Institute for Human-Centered Artificial Intelligence (HAI). The AI Index Report tracks, collates, distills, and visualizes data related to artificial intelligence. Its mission is to provide unbiased, rigorously vetted, and globally sourced data for policymakers, researchers, executives, journalists, and the general public to develop intuitions about the complex field of AI. The report aims to be the most credible and authoritative source for data and insights about AI in the world.

This paper investigates the problem of impact-time-control and proposes a learning-based computational guidance algorithm to solve this problem. The proposed guidance algorithm is developed based on a general prediction-correction concept: the exact time-to-go under proportional navigation guidance with realistic aerodynamic characteristics is estimated by a deep neural network and a biased command to nullify the impact time error is developed by utilizing the emerging reinforcement learning techniques. The deep neural network is augmented into the reinforcement learning block to resolve the issue of sparse reward that has been observed in typical reinforcement learning formulation. Extensive numerical simulations are conducted to support the proposed algorithm.

Restless Multi-Armed Bandits (RMABs) have been popularly used to model limited resource allocation problems. Recently, these have been employed for health monitoring and intervention planning problems. However, the existing approaches fail to account for the arrival of new patients and the departure of enrolled patients from a treatment program. To address this challenge, we formulate a streaming bandit (S-RMAB) framework, a generalization of RMABs where heterogeneous arms arrive and leave under possibly random streams. We propose a new and scalable approach to computing index-based solutions. We start by proving that index values decrease for short residual lifetimes, a phenomenon that we call index decay. We then provide algorithms designed to capture index decay without having to solve the costly finite horizon problem, thereby lowering the computational complexity compared to existing methods.We evaluate our approach via simulations run on real-world data obtained from a tuberculosis intervention planning task as well as multiple other synthetic domains. Our algorithms achieve an over 150x speed-up over existing methods in these tasks without loss in performance. These findings are robust across multiple domains.

Translating between languages where certain features are marked morphologically in one but absent or marked contextually in the other is an important test case for machine translation. When translating into English which marks (in)definiteness morphologically, from Yor\`ub\'a which uses bare nouns but marks these features contextually, ambiguities arise. In this work, we perform fine-grained analysis on how an SMT system compares with two NMT systems (BiLSTM and Transformer) when translating bare nouns in Yor\`ub\'a into English. We investigate how the systems what extent they identify BNs, correctly translate them, and compare with human translation patterns. We also analyze the type of errors each model makes and provide a linguistic description of these errors. We glean insights for evaluating model performance in low-resource settings. In translating bare nouns, our results show the transformer model outperforms the SMT and BiLSTM models for 4 categories, the BiLSTM outperforms the SMT model for 3 categories while the SMT outperforms the NMT models for 1 category.

DUBAI, United Arab Emirates (AP) -- A pair of B-52 bombers flew over the Mideast on Sunday, the latest such mission in the region aimed at warning Iran amid tensions between Washington and Tehran. The flight by the two heavy bombers came as a pro-Iran satellite channel based in Beirut broadcast Iranian military drone footage of an Israeli ship hit by a mysterious explosion only days earlier in the Mideast. While the channel sought to say Iran wasn't involved, Israel has blamed Tehran for what it described as an attack on the vessel. The U.S. military's Central Command said the two B-52s flew over the region accompanied by military aircraft from nations including Israel, Saudi Arabia and Qatar. It marked the fourth-such bomber deployment into the Mideast this year and the second under President Joe Biden.

Harm wrought by AI tends to fall most heavily on marginalized communities. In the United States, algorithmic harm may lead to the false arrest of Black men, disproportionately reject female job candidates, or target people who identify as queer. In India, those impacts can further impact marginalized populations like Muslim minority groups or people oppressed by the caste system. And algorithmic fairness frameworks developed in the West may not transfer directly to people in India or other countries in the Global South, where algorithmic fairness requires understanding of local social structures and power dynamics and a legacy of colonialism. That's the argument behind "De-centering Algorithmic Power: Towards Algorithmic Fairness in India," a paper accepted for publication at the Fairness, Accountability, and Transparency (FAccT) conference, which begins this week. Other works that seek to move beyond a Western-centric focus include Shinto or Buddhism-based frameworks for AI design and an approach to AI governance based on the African philosophy of Ubuntu.

The information presented in Lega-Tech Artificial Intelligence Market Report 2021 includes qualitative and quantitative insights. Under the qualitative analysis part, manufacturing base, raw materials data, Lega-Tech Artificial Intelligence status, trends, SWOT analysis, PESTEL Analysis, distribution channels, driving factors, and a competitive structure is presented. Under the qualitative analysis part, market value/volume, production analysis, consumption data, import-export data, or each region and country are explained. Also, industry size by Lega-Tech Artificial Intelligence type, application, demand and supply scenario, and economic status are explained. Also, comprehensive information on the latest product development, growth opportunities, industry strategies, cost structures, and recent policies are enlightened in the Lega-Tech Artificial Intelligence report.

What are the opportunities and threats faced by the vendors in the international market?