Mean field control (MFC) problems have been introduced to study social optima in very large populations of strategic agents. The main idea is to consider an infinite population and to simplify the analysis by using a mean field approximation. These problems can also be viewed as optimal control problems for McKean-Vlasov dynamics. They have found applications in a wide range of fields, from economics and finance to social sciences and engineering. Usually, the goal for the agents is to minimize a total cost which consists in the integral of a running cost plus a terminal cost. In this work, we consider MFC problems in which there is no terminal cost but, instead, the terminal distribution is prescribed. We call such problems mean field optimal transport problems since they can be viewed as a generalization of classical optimal transport problems when mean field interactions occur in the dynamics or the running cost function. We propose three numerical methods based on neural networks. The first one is based on directly learning an optimal control. The second one amounts to solve a forward-backward PDE system characterizing the solution. The third one relies on a primal-dual approach. We illustrate these methods with numerical experiments conducted on two families of examples.

Welcome to the wild world of software and carbon emissions, where the digital infrastructure of organizations is a hungry beast, consuming vast amounts of electricity and leaving a trail of greenhouse gas emissions in its wake. The issue is becoming more pronounced as the world accelerates its adoption of artificial intelligence and businesses increasingly rely on software to drive their operations. Picture a data center, a fortress of technology where much of today's software is housed. These sprawling structures gobble up electricity with reckless abandon, with worldwide consumption estimated to be between 220 to 320 terawatt-hours in 2021, according to the International Energy Agency. That's more power than consumed by entire countries such as South Africa, Sweden, or Egypt.

The graph represents a network of 670 Twitter users whose recent tweets contained "NodeXL", or who were replied to, mentioned, retweeted or quoted in those tweets, taken from a data set limited to a maximum of 20,000 tweets, tweeted between 2/14/2023 9:49:15 AM and 2/21/2023 9:49:15 AM. The network was obtained from Twitter on Tuesday, 21 February 2023 at 17:50 UTC. The tweets in the network were tweeted over the 1376-day, 0-hour, 38-minute period from Friday, 17 May 2019 at 17:01 UTC to Tuesday, 21 February 2023 at 17:39 UTC. There is an edge for each "replies-to" relationship in a tweet, an edge for each "mentions" relationship in a tweet, an edge for each "retweet" relationship in a tweet, an edge for each "quote" relationship in a tweet, an edge for each "mention in retweet" relationship in a tweet, an edge for each "mention in reply-to" relationship in a tweet, an edge for each "mention in quote" relationship in a tweet, an edge for each "mention in quote reply-to" relationship in a tweet, and a self-loop edge for each tweet that is not from above. The graph's vertices were grouped by cluster using the Clauset-Newman-Moore cluster algorithm.

Like so many cities before it, Phoenix went all out to host the Super Bowl earlier this month. Expecting about 1 million fans to come to town for the biggest American sporting event of the year, the city rolled out a fleet of self-driving electric vehicles to ferry visitors from the airport. Robots sifted through the trash to pull out anything that could be composted. There were less visible developments, too. In preparation for the game, the local authorities upgraded a network of cameras around the city's downtown--and have kept them running after the spectators have left.

Over the past ten years, Artificial Intelligence (AI) and Machine Learning (ML) have steadily crept into the Art Industry. From Deepfakes to DALL·E, the impact of these new technologies can be longer be ignored, and many communities are now on the edge of a reckoning. On one side, the potential for modern AIs to generate and edit both images and videos is opening new job opportunities for millions; but on the other is also threatening a sudden and disruptive change across many industries. The purpose of this long article is to serve as an introduction to the complex topic of AI Art: from the technologies that are powering this revolution, to the ethical and legal issues they have unleashed. While this is still an ongoing conversation, I hope it will serve as a primer for anyone interested in better understanding these phenomena--especially journalists who are keen to learn more about the benefits, changes and challenges that that AI will inevitably bring into our own lives.

Improving sample efficiency is a key challenge in reinforcement learning, especially in environments with large state spaces and sparse rewards. In literature, this is resolved either through the use of auxiliary tasks (subgoals) or through clever exploration strategies. Exploration methods have been used to sample better trajectories in large environments while auxiliary tasks have been incorporated where the reward is sparse. However, few studies have attempted to tackle both large scale and reward sparsity at the same time. This paper explores the idea of combining exploration with auxiliary task learning using General Value Functions (GVFs) and a directed exploration strategy. We present a way to learn value functions which can be used to sample actions and provide directed exploration. Experiments on navigation tasks with varying grid sizes demonstrate the performance advantages over several competitive baselines.

This paper introduces a new sparse Bayesian learning (SBL) algorithm that jointly recovers a temporal sequence of edge maps from noisy and under-sampled Fourier data. The new method is cast in a Bayesian framework and uses a prior that simultaneously incorporates intra-image information to promote sparsity in each individual edge map with inter-image information to promote similarities in any unchanged regions. By treating both the edges as well as the similarity between adjacent images as random variables, there is no need to separately form regions of change. Thus we avoid both additional computational cost as well as any information loss resulting from pre-processing the image. Our numerical examples demonstrate that our new method compares favorably with more standard SBL approaches.

Binary geospatial data is commonly analyzed with generalized linear mixed models, specified with a linear fixed covariate effect and a Gaussian Process (GP)-distributed spatial random effect, relating to the response via a link function. The assumption of linear covariate effects is severely restrictive. Random Forests (RF) are increasingly being used for non-linear modeling of spatial data, but current extensions of RF for binary spatial data depart the mixed model setup, relinquishing inference on the fixed effects and other advantages of using GP. We propose RF-GP, using Random Forests for estimating the non-linear covariate effect and Gaussian Processes for modeling the spatial random effects directly within the generalized mixed model framework. We observe and exploit equivalence of Gini impurity measure and least squares loss to propose an extension of RF for binary data that accounts for the spatial dependence. We then propose a novel link inversion algorithm that leverages the properties of GP to estimate the covariate effects and offer spatial predictions. RF-GP outperforms existing RF methods for estimation and prediction in both simulated and real-world data. We establish consistency of RF-GP for a general class of $\beta$-mixing binary processes that includes common choices like spatial Mat\'ern GP and autoregressive processes.

Autonomous driving (AD) and advanced driver assistance systems (ADAS) increasingly utilize deep neural networks (DNNs) for improved perception or planning. Nevertheless, DNNs are quite brittle when the data distribution during inference deviates from the data distribution during training. This represents a challenge when deploying in partly unknown environments like in the case of ADAS. At the same time, the standard confidence of DNNs remains high even if the classification reliability decreases. This is problematic since following motion control algorithms consider the apparently confident prediction as reliable even though it might be considerably wrong. To reduce this problem real-time capable confidence estimation is required that better aligns with the actual reliability of the DNN classification. Additionally, the need exists for black-box confidence estimation to enable the homogeneous inclusion of externally developed components to an entire system. In this work we explore this use case and introduce the neighborhood confidence (NHC) which estimates the confidence of an arbitrary DNN for classification. The metric can be used for black-box systems since only the top-1 class output is required and does not need access to the gradients, the training dataset or a hold-out validation dataset. Evaluation on different data distributions, including small in-domain distribution shifts, out-of-domain data or adversarial attacks, shows that the NHC performs better or on par with a comparable method for online white-box confidence estimation in low data regimes which is required for real-time capable AD/ADAS.

With the widespread use of knowledge graphs (KG) in various automated AI systems and applications, it is very important to ensure that information retrieval algorithms leveraging them are free from societal biases. Previous works have depicted biases that persist in KGs, as well as employed several metrics for measuring the biases. However, such studies lack the systematic exploration of the sensitivity of the bias measurements, through varying sources of data, or the embedding algorithms used. To address this research gap, in this work, we present a holistic analysis of bias measurement on the knowledge graph. First, we attempt to reveal data biases that surface in Wikidata for thirteen different demographics selected from seven continents. Next, we attempt to unfold the variance in the detection of biases by two different knowledge graph embedding algorithms - TransE and ComplEx. We conduct our extensive experiments on a large number of occupations sampled from the thirteen demographics with respect to the sensitive attribute, i.e., gender. Our results show that the inherent data bias that persists in KG can be altered by specific algorithm bias as incorporated by KG embedding learning algorithms. Further, we show that the choice of the state-of-the-art KG embedding algorithm has a strong impact on the ranking of biased occupations irrespective of gender. We observe that the similarity of the biased occupations across demographics is minimal which reflects the socio-cultural differences around the globe. We believe that this full-scale audit of the bias measurement pipeline will raise awareness among the community while deriving insights related to design choices of data and algorithms both and refrain from the popular dogma of ``one-size-fits-all''.