Agents
Chat: Humans v Bots Or A Blend Of Both?
This has been a repeated news item in the business media for a few years now. As automated systems and Artificial Intelligence (AI) gets better and better customer service agents will watch their jobs disappear – stolen by robots and software agents. The reality is far more complex because there are many reasons why a customer gets in touch with customer service. It could be a very simple requirement, like a password reset, or an application for a new mortgage that will require a detailed conversation with a great deal of personal information and documentation. There is no single type of customer service interaction and therefore one of the initial challenges that companies have found is deciding when an interaction can be automated and when a human should handle the interaction.
Do We Trust Artificial Intelligence Agents to Mediate Conflict? Not Entirely - Express Computer
We may listen to facts from Siri or Alexa, or directions from Google Maps or Waze, but would we let a virtual agent enabled by artificial intelligence help mediate conflict among team members? A new study says not just yet. Researchers from the University of Southern California (USC) and the University of Denver created a simulation in which a three-person team was supported by a virtual agent avatar on screen in a mission that was designed to ensure failure and elicit conflict. The study was designed to look at virtual agents as potential mediators to improve team collaboration during conflict mediation. But in the heat of the moment, will we listen to virtual agents?
Multi-agent Inverse Reinforcement Learning for Certain General-sum Stochastic Games
Lin, Xiaomin (University of Virginia) | Adams, Stephen C. (University of Virginia) | Beling, Peter A. (University of Virginia)
This paper addresses the problem of multi-agent inverse reinforcement learning (MIRL) in a two-player general-sum stochastic game framework. Five variants of MIRL are considered: uCS-MIRL, advE-MIRL, cooE-MIRL, uCE-MIRL, and uNE-MIRL, each distinguished by its solution concept. Problem uCS-MIRL is a cooperative game in which the agents employ cooperative strategies that aim to maximize the total game value. In problem uCE-MIRL, agents are assumed to follow strategies that constitute a correlated equilibrium while maximizing total game value. Problem uNE-MIRL is similar to uCE-MIRL in total game value maximization, but it is assumed that the agents are playing a Nash equilibrium. Problems advE-MIRL and cooE-MIRL assume agents are playing an adversarial equilibrium and a coordination equilibrium, respectively. We propose novel approaches to address these five problems under the assumption that the game observer either knows or is able to accurately estimate the policies and solution concepts for players. For uCS-MIRL, we first develop a characteristic set of solutions ensuring that the observed bi-policy is a uCS and then apply a Bayesian inverse learning method. For uCE-MIRL, we develop a linear programming problem subject to constraints that define necessary and sufficient conditions for the observed policies to be correlated equilibria. The objective is to choose a solution that not only minimizes the total game value difference between the observed bi-policy and a local uCS, but also maximizes the scale of the solution. We apply a similar treatment to the problem of uNE-MIRL. The remaining two problems can be solved efficiently by taking advantage of solution uniqueness and setting up a convex optimization problem. Results are validated on various benchmark grid-world games.
SafeCritic: Collision-Aware Trajectory Prediction
van der Heiden, Tessa, Nagaraja, Naveen Shankar, Weiss, Christian, Gavves, Efstratios
Navigating complex urban environments safely is a key to realize fully autonomous systems. Predicting future locations of vulnerable road users, such as pedestrians and cyclists, thus, has received a lot of attention in the recent years. While previous works have addressed modeling interactions with the static (obstacles) and dynamic (humans) environment agents, we address an important gap in trajectory prediction. We propose SafeCritic, a model that synergizes generative adversarial networks for generating multiple "real" trajectories with reinforcement learning to generate "safe" trajectories. The Discriminator evaluates the generated candidates on whether they are consistent with the observed inputs. The Critic network is environmentally aware to prune trajectories that are in collision or are in violation with the environment. The auto-encoding loss stabilizes training and prevents mode-collapse. We demonstrate results on two large scale data sets with a considerable improvement over state-of-the-art. We also show that the Critic is able to classify the safety of trajectories.
An Option and Agent Selection Policy with Logarithmic Regret for Multi Agent Multi Armed Bandit Problems on Random Graphs
Pankayaraj, Pathmanathan, Maithripala, D. H. S.
Existing studies of the Multi Agent Multi Armed Bandit (MAMAB) problem, with the exception of a very few, consider the case where the agents observe their neighbors according to a static network graph. They also mostly rely on a running consensus for the estimation of the option rewards. Two of the exceptions consider a problem where agents observe instantaneous rewards and actions of their neighbors through an iid ER graph process based communication strategy. In this paper we propose a UCB based option allocation rule that guarantees logarithmic regret even if the graph depends on the history of choices made by the agents. The paper also proposes a novel communication strategy that significantly outperforms the iid ER graph based communication strategy. In both the ER graph and the dependent graph strategy, the regret is shown to depend on the connectivity of the graph in a particularly interesting way where there exists an optimal connectivity of the graph that is less than the full connectivity of the graph.
Challenges of Human-Aware AI Systems
From its inception, AI has had a rather ambivalent relationship to humans---swinging between their augmentation and replacement. Now, as AI technologies enter our everyday lives at an ever increasing pace, there is a greater need for AI systems to work synergistically with humans. To do this effectively, AI systems must pay more attention to aspects of intelligence that helped humans work with each other---including social intelligence. I will discuss the research challenges in designing such human-aware AI systems, including modeling the mental states of humans in the loop, recognizing their desires and intentions, providing proactive support, exhibiting explicable behavior, giving cogent explanations on demand, and engendering trust. I will survey the progress made so far on these challenges, and highlight some promising directions. I will also touch on the additional ethical quandaries that such systems pose. I will end by arguing that the quest for human-aware AI systems broadens the scope of AI enterprise, necessitates and facilitates true inter-disciplinary collaborations, and can go a long way towards increasing public acceptance of AI technologies.
Multiagent Rollout Algorithms and Reinforcement Learning
We consider finite and infinite horizon dynamic programming problems, where the control at each stage consists of several distinct decisions, each one made by one of several agents. We introduce an algorithm, whereby at every stage, each agent's decision is made by executing a local rollout algorithm that uses a base policy, together with some coordinating information from the other agents. The amount of local computation required at every stage by each agent is independent of the number of agents, while the amount of global computation (over all agents) grows linearly with the number of agents. By contrast, with the standard rollout algorithm, the amount of global computation grows exponentially with the number of agents. Despite the drastic reduction in required computation, we show that our algorithm has the fundamental cost improvement property of rollout: an improved performance relative to the base policy. We also explore related reinforcement learning and approximate policy iteration algorithms, and we discuss how this cost improvement property is affected when we attempt to improve further the method's computational efficiency through parallelization of the agents' computations.
Optimal Clustering from Noisy Binary Feedback
Ariu, Kaito, Ok, Jungseul, Proutiere, Alexandre, Yun, Se-Young
We study the problem of recovering clusters from binary user feedback. Items are grouped into initially unknown non-overlapping clusters. To recover these clusters, the learner sequentially presents to users a finite list of items together with a question with a binary answer selected from a fixed finite set. For each of these items, the user provides a random answer whose expectation is determined by the item cluster and the question and by an item-specific parameter characterizing the hardness of classifying the item. The objective is to devise an algorithm with a minimal cluster recovery error rate. We derive problem-specific information-theoretical lower bounds on the error rate satisfied by any algorithm, for both uniform and adaptive (list, question) selection strategies. For uniform selection, we present a simple algorithm built upon K-means whose performance almost matches the fundamental limits. For adaptive selection, we develop an adaptive algorithm that is inspired by the derivation of the information-theoretical error lower bounds, and in turn allocates the budget in an efficient way. The algorithm learns to select items hard to cluster and relevant questions more often. We compare numerically the performance of our algorithms with or without adaptive selection strategy, and illustrate the gain achieved by being adaptive. Our inference problems are motivated by the problem of solving large-scale labeling tasks with minimal effort put on the users. For example, in some of the recent CAPTCHA systems, users clicks (binary answers) can be used to efficiently label images, by optimally finding the best questions to present.
Visual Hide and Seek
Chen, Boyuan, Song, Shuran, Lipson, Hod, Vondrick, Carl
V ISUAL HIDE AND SEEK Boyuan Chen Columbia University Shuran Song Columbia University Hod Lipson Columbia University Carl V ondrick Columbia University A BSTRACT We train embodied agents to play Visual Hide and Seek where a prey must navigate in a simulated environment in order to avoid capture from a predator. We place a variety of obstacles in the environment for the prey to hide behind, and we only give the agents partial observations of their environment using an egocentric perspective. Although we train the model to play this game from scratch, experiments and visualizations suggest that the agent learns to predict its own visibility in the environment. Furthermore, we quantitatively analyze how agent weaknesses, such as slower speed, effect the learned policy. Our results suggest that, although agent weaknesses make the learning problem more challenging, they also cause more useful features to be learned. Our project website is available at: http://www.cs.columbia.edu/ We designed this game to mimic the typical dynamics between predator and prey. For example, we place a variety of obstacles inside the environment, which create occlusions that the agent can leverage to hide behind. We also only give the agents access to the first-person perspective of their three-dimensional environment. Consequently, this task is a substantial challenge for reinforcement learning because the state is both visual (pixel input) and partially observable (due to occlusions).
Federated Transfer Reinforcement Learning for Autonomous Driving
Liang, Xinle, Liu, Yang, Chen, Tianjian, Liu, Ming, Yang, Qiang
Xinle Liang 1, Y ang Liu 1, Tianjian Chen 1, Ming Liu 2 and Qiang Y ang 1 Abstract -- Reinforcement learning (RL) is widely used in autonomous driving tasks and training RL models typically involves in a multi-step process: pre-training RL models on simulators, uploading the pre-trained model to real-life robots, and fine-tuning the weight parameters on robot vehicles. This sequential process is extremely time-consuming and more importantly, knowledge from the fine-tuned model stays local and can not be reused or leveraged collaboratively. T o tackle this problem, we present an online federated RL transfer process for real-time knowledge extraction where all the participant agents make corresponding actions with the knowledge learned by others, even when they are acting in very different environments. T o validate the effectiveness of the proposed approach, we constructed a real-life collision avoidance system with Microsoft Airsim simulator and NVIDIA JetsonTX2 car agents, which cooperatively learn from scratch to avoid collisions in indoor environment with obstacle objects. We demonstrate that with the proposed framework, the simulator car agents can transfer knowledge to the RC cars in real-time, with 27% increase in the average distance with obstacles and 42% decrease in the collision counts. I. INTRODUCTION Recent Reinforcement Learning (RL) researches in autonomous robots have achieved significant performance improvement by employing distributed architecture for decentralized agents [1], [2], which is termed as Distributed Reinforcement Learning (DRL). However, most existing DRL frameworks consider only synchronous learning with a constant environment.